GENERAL BIOLOGY TEACHING GUIDE

GENERAL BIOLOGY TEACHING GUIDE
Teaching Guide for Senior High School GENERAL BIOLOGY 1 SPECIALIZED SUBJECT | ACADEMIC - STEM This Teaching Guide was collaboratively developed and reviewed by educators from public and private schools, colleges, and universities. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the Commission on Higher Education, K to 12 Transition Program Management Unit - Senior High School Support Team at k12@ched.gov.ph. We value your feedback and recommendations. The Commission on Higher Education in collaboration with the Philippine Normal University INITIAL RELEASE: 13 JUNE 2016
This Teaching Guide by the Commission on Higher Education is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. This means you are free to: Share — copy and redistribute the material in any medium or format Adapt — remix, transform, and build upon the material. The licensor, CHED, cannot revoke these freedoms as long as you follow the license terms. However, under the following terms: Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. NonCommercial — You may not use the material for commercial purposes. ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. Development Team Team Leader: Florencia G. Claveria, Ph.D.,   Dawn T. Crisologo Writers: Doreen D. Domingo, Ph.D., Janet S. Estacion, Ph.D., Mary Jane C. Flores, Ph.D.,   Aileen C. dela Cruz, Chuckie Fer Calsado,   Nolasco H. Sablan, Justin Ray M. Guce Technical Editor: John Donnie A. Ramos, Ph.D. Copy Reader: Joy R. Jimena Illustrators: Renan U. Ortiz, Daniela Louise B. Go Cover Artists: Paolo Kurtis N. Tan, Renan U. Ortiz Published by the Commission on Higher Education, 2016  Chairperson: Patricia B. Licuanan, Ph.D. Commission on Higher Education  K to 12 Transition Program Management Unit  Office Address: 4th Floor, Commission on Higher Education, C.P. Garcia Ave., Diliman, Quezon City  Telefax: (02) 441-0927 / E-mail Address: k12@ched.gov.ph Senior High School Support Team  CHED K to 12 Transition Program Management Unit Program Director: Karol Mark R. Yee Lead for Senior High School Support:  Gerson M. Abesamis Course Development Officers:  John Carlo P. Fernando, Danie Son D. Gonzalvo Lead for Policy Advocacy and Communications:  Averill M. Pizarro Teacher Training Officers:  Ma. Theresa C. Carlos, Mylene E. Dones Monitoring and Evaluation Officer:  Robert Adrian N. Daulat Administrative Officers:   Ma. Leana Paula B. Bato, Kevin Ross D. Nera, Allison A. Danao, Ayhen Loisse B. Dalena Printed in the Philippines by EC-TEC Commercial, No. 32 St. Louis Compound 7, Baesa, Quezon City, ectec_com@yahoo.com Consultants THIS PROJECT WAS DEVELOPED WITH THE PHILIPPINE NORMAL UNIVERSITY.  University President: Ester B. Ogena, Ph.D.  VP for Academics: Ma. Antoinette C. Montealegre, Ph.D.  VP for University Relations & Advancement: Rosemarievic V. Diaz, Ph.D. Ma. Cynthia Rose B. Bautista, Ph.D., CHED  Bienvenido F. Nebres, S.J., Ph.D., Ateneo de Manila University  Carmela C. Oracion, Ph.D., Ateneo de Manila University  Minella C. Alarcon, Ph.D., CHED Gareth Price, Sheffield Hallam University  Stuart Bevins, Ph.D., Sheffield Hallam University
Table of Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 DepEd General Biology 1 Curriculum Guide . . . . . . . . . . . . . 5 Chapter 3: Energy Transformation Chapter 1: Cell Lesson 11: Photosynthesis and Cellular Respiration . . . . . . . . . . . 86 Lesson 1: The Cell: Endomembrane System, Mitochondria, Chloroplasts, Cytoskeleton, and Extracellular Components . . . 9 Lesson 12: Forms of Energy, Laws of Energy Transformation and Role of ATP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Lesson 2: Mitochondria and Chloroplasts . . . . . . . . . . . . . . . . . 15 Lesson 13: Energy Transformation Part 1 . . . . . . . . . . . . . . . . . . . . 111 Lesson 3: Structure and Functions of Animal Tissues and Cell Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Lesson 14: Energy Transformation Part 2 . . . . . . . . . . . . . . . . . . . . Lesson 15: Energy Transformation Part 3 . . . . . . . . . . . . . . . . . . . . 120 128 Lesson 4: Cell Cycle and Cell Division . . . . . . . . . . . . . . . . . . . . 36 Lesson 16: Cellular Respiration Part 1 . . . . . . . . . . . . . . . . . . . . . . 133 Lesson 5: Transport Mechanisms Part 1 . . . . . . . . . . . . . . . . . . . 46 Lesson 17: Cellular Respiration Part 2 . . . . . . . . . . . . . . . . . . . . . . 150 Lesson 6: Transport Mechanisms Part 2 . . . . . . . . . . . . . . . . . . . 50 Lesson 18: Cellular Respiration Part 3 . . . . . . . . . . . . . . . . . . . . . . 165 Chapter 2: Biological Molecules Lesson 19: ATP in Cellular Metabolism and Photosynthesis . . . . . 176 Lesson 7: Carbohydrates and Lipids . . . . . . . . . . . . . . . . . . . . . 57 Lesson 8: Amino Acids and Proteins Part 1 . . . . . . . . . . . . . . . . 70 Biographical Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Lesson 9: Amino Acids and Proteins Part 2 . . . . . . . . . . . . . . . . 73 Lesson 10: Biological Molecules: Enzymes . . . . . . . . . . . . . . . . 78
Introduction As the Commission supports DepEd’s implementation of Senior High School (SHS), it upholds the vision and mission of the K to 12 program, stated in Section 2 of Republic Act 10533, or the Enhanced Basic Education Act of 2013, that “every graduate of basic education be an empowered individual, through a program rooted on...the competence to engage in work and be productive, the ability to coexist in fruitful harmony with local and global communities, the capability to engage in creative and critical thinking, and the capacity and willingness to transform others and oneself.” To accomplish this, the Commission partnered with the Philippine Normal University (PNU), the National Center for Teacher Education, to develop Teaching Guides for Courses of SHS. Together with PNU, this Teaching Guide was studied and reviewed by education and pedagogy experts, and was enhanced with appropriate methodologies and strategies. Furthermore, the Commission believes that teachers are the most important partners in attaining this goal. Incorporated in this Teaching Guide is a framework that will guide them in creating lessons and assessment tools, support them in facilitating activities and questions, and assist them towards deeper content areas and competencies. Thus, the introduction of the SHS for SHS Framework. The SHS for SHS Framework, which stands for “Saysay-Husay-Sarili for Senior High School,” is at the core of this book. The lessons, which combine high-quality content with flexible elements to accommodate diversity of teachers and environments, promote these three fundamental concepts: SAYSAY: MEANING Why is this important? Through this Teaching Guide, teachers will be able to facilitate an understanding of the value of the lessons, for each learner to fully engage in the content on both the cognitive and affective levels. HUSAY: MASTERY How will I deeply understand this? Given that developing mastery goes beyond memorization, teachers should also aim for deep understanding of the subject matter where they lead learners to analyze and synthesize knowledge. SARILI: OWNERSHIP What can I do with this? When teachers empower learners to take ownership of their learning, they develop independence and self- direction, learning about both the subject matter and themselves. SHS for SHS Framework
Biology I is a Science, Technology, Engineering and Mathematics (STEM) Specialized Subject taken in the first half of Grades 11/12. Learners go on a journey geared toward the deeper understanding and appreciation of life processes at the cellular and molecular levels previously introduced in Grades 7-10. They will also apply basic chemistry and physics principles as they examine the transformation of energy in organisms. Implementing this course at the senior high school level is subject to numerous challenges with mastery of content among educators tapped to facilitate learning and a lack of resources to deliver the necessary content and develop skills and attitudes in the learners, being foremost among these. In support of the SHS for SHS framework developed by CHED, these teaching guides were crafted and refined by biologists and biology educators in partnership with educators from focus groups all over the Philippines to provide opportunities to develop the following: Saysay through meaningful, updated, and context-specific content that highlights important points and common misconceptions so that learners can connect to their real-world experiences and future careers; Husay through diverse learning experiences that can be implemented in a resource-poor classroom or makeshift laboratory that tap cognitive, affective, and psychomotor domains are accompanied by field-tested teaching tips that aid in facilitating discovery and development of higher-order thinking skills; and Sarili through flexible and relevant content and performance standards allow learners the freedom to innovate, make their own decisions, and initiate activities to fully develop their academic and personal potential. These ready-to-use guides are helpful to educators new to either the content or biologists new to the experience of teaching Senior High School due to their enriched content presented as lesson plans or guides. Veteran educators may also add ideas from these guides to their repertoire. The Biology Team hopes that this resource may aid in easing the transition of the different stakeholders into the new curriculum as we move towards the constant improvement of Philippine education. About this  Teaching Guide
This Teaching Guide is mapped and aligned to the DepEd SHS Curriculum, designed to be highly usable for teachers. It contains classroom activities and pedagogical notes, and is integrated with innovative pedagogies. All of these elements are presented in the following parts: 1. Introduction • Highlight key concepts and identify the essential questions • Show the big picture • Connect and/or review prerequisite knowledge • Clearly communicate learning competencies and objectives • Motivate through applications and connections to real-life 2. Motivation • Give local examples and applications • Engage in a game or movement activity • Provide a hands-on/laboratory activity • Connect to a real-life problem 3. Instruction/Delivery • Give a demonstration/lecture/simulation/hands-on activity • Show step-by-step solutions to sample problems • Give applications of the theory • Connect to a real-life problem if applicable 4. Practice • Discuss worked-out examples • Provide easy-medium-hard questions • Give time for hands-on unguided classroom work and discovery • Use formative assessment to give feedback 5. Enrichment • Provide additional examples and applications • Introduce extensions or generalisations of concepts • Engage in reflection questions • Encourage analysis through higher order thinking prompts 6. Evaluation • Supply a diverse question bank for written work and exercises • Provide alternative formats for student work: written homework, journal, portfolio, group/individual projects, student-directed research project Parts of the  Teaching Guide
As Higher Education Institutions (HEIs) welcome the graduates of the Senior High School program, it is of paramount importance to align Functional Skills set by DepEd with the College Readiness Standards stated by CHED. The DepEd articulated a set of 21st century skills that should be embedded in the SHS curriculum across various subjects and tracks. These skills are desired outcomes that K to 12 graduates should possess in order to proceed to either higher education, employment, entrepreneurship, or middle-level skills development. On the other hand, the Commission declared the College Readiness Standards that consist of the combination of knowledge, skills, and reflective thinking necessary to participate and succeed - without remediation - in entry-level undergraduate courses in college. The alignment of both standards, shown below, is also presented in this Teaching Guide - prepares Senior High School graduates to the revised college curriculum which will initially be implemented by AY 2018-2019. College Readiness Standards Foundational Skills DepEd Functional Skills Produce all forms of texts (written, oral, visual, digital) based on: 1. Solid grounding on Philippine experience and culture; 2. An understanding of the self, community, and nation; 3. Application of critical and creative thinking and doing processes; 4. Competency in formulating ideas/arguments logically, scientifically, and creatively; and 5. Clear appreciation of one’s responsibility as a citizen of a multicultural Philippines and a diverse world; Visual and information literacies, media literacy, critical thinking and problem solving skills, creativity, initiative and self-direction Systematically apply knowledge, understanding, theory, and skills for the development of the self, local, and global communities using prior learning, inquiry, and experimentation Global awareness, scientific and economic literacy, curiosity, critical thinking and problem solving skills, risk taking, flexibility and adaptability, initiative and self-direction Work comfortably with relevant technologies and develop adaptations and innovations for significant use in local and global communities Global awareness, media literacy, technological literacy, creativity, flexibility and adaptability, productivity and accountability Communicate with local and global communities with proficiency, orally, in writing, and through new technologies of communication Global awareness, multicultural literacy, collaboration and interpersonal skills, social and cross-cultural skills, leadership and responsibility Interact meaningfully in a social setting and contribute to the fulfilment of individual and shared goals, respecting the fundamental humanity of all persons and the diversity of groups and communities Media literacy, multicultural literacy, global awareness, collaboration and interpersonal skills, social and cross-cultural skills, leadership and responsibility, ethical, moral, and spiritual values On DepEd Functional Skills and CHED College Readiness Standards
General Biology 1 The Cell: Endomembrane System, Mitochondria, Chloroplasts, Cytoskeleton, and Extracellular Components Content Standards The learners demonstrate an understanding of (1) Composition of the endomembrane system; (2) Structure and function of organelles involved in energy transformation; (3) Structure and functions of the cytoskeleton; and, (4) Composition and functions of the extracellular components or matrix. Performance Standards The learners shall be able to construct three-dimensional models of whole cells using indigenous or recyclable materials. The models shall show the following cell parts: (1) Endomembrane System, (2) Mitochondria, and (3) Chloroplast Learning Competencies The learners: (1) explain the postulates of the cell theory (STEM_BIO11/12-1a- c-1); (2) describe the structure and function of major and subcellular organelles (STEM_BIO11/12-Ia-c-2); (3) describe the structural components of the cell membrane (STEM_BIO11/12-Ig-h-11); and (4) relate the structure and composition of the cell membrane to its function (STEM_BIO11/12-Ig-h-12) Specific Learning Outcomes At the end of the unit lesson, the learners shall be able to: • illustrate the structure of the endomembrane system, label its parts, and understand how the system works • illustrate the structure of the mitochondria, label its parts, and understand the importance of the enfolding of the inner mitochondrial membrane • illustrate the structure of the chloroplast, label its parts, and relate these parts to photosynthesis • understand the connection of the endomembrane system to other cell parts such as the lysosomes, peroxisomes, endosomes, and cell membrane • understand how the extracellular components or matrix determine the appearance and function of the tissues  60 MINS LESSON OUTLINE Introduction Review on the differences between prokaryotic and eukaryotic cells; submission and discussion of responses to the pre-topic homework assigned before the lecture. 5 Motivation Brief class activity on prokaryotic and eukaryotic cells. 5 Instruction/ Practice Lecture. Board work on cell parts, structure, and function. Examination of cheek cells and Hydrilla cells under a microscope. Class activity on identifying the parts and functions of the endomembrane system. 40 Enrichment Class discussion on cell size and relationship of surface area and volume 5 Evaluation Assessment of learners’ knowledge; assignment of homework for next lecture 5 Materials microscope (slide, cover slip), hand-held lens, work books, methylene blue, plastic spoon/popsicle stick, Hydrilla plansts, colored chalk/white board marker Resources (continued at the end of Teaching Guide) (1) (n.d.). Retrieved from <http://www.phschool.com/science/ biology_place/biocoach/cells/common.html> (2) (n.d.). Retrieved from <http://biology.tutorvista.com/animal-and-plant- (3) (n.d.). Retrieved from <http://sciencenetlinks.com/lessons/cells-2-the- cell-as-a-system/>
INTRODUCTION (5 MINS) 1. Ask the learners to make a recap of the differences between prokaryotic and eukaryotic cells. 2. Discuss the learners’ responses to the pre-topic assignment on the functions of the following cell parts: • Nucleus • Smooth Endoplasmic Reticulum • Rough Endoplasmic Reticulum • Golgi Apparatus • Ribosomes • Lysosomes • Mitochondria • Chloroplast 3. Present an overview of the cell membrane, its structure, and functions. 4. Define what an ‘organelle’ is and differentiate membrane-bound organelles from non-membrane- bound organelles. 5. Explain that in eukaryotic cells, the machinery of the cell is compartmentalized into organelles. The compartmentalization of the cell into membrane-bound organelles: • allows conflicting functions (i.e., synthesis vs. breakdown) and several cellular activities to occur simultaneously without interference from each other • separates the DNA material of the nucleus, mitochondria, and chloroplast • increases the surface area-volume ratio of the cell 6. Encourage the learners to look at the cell as both a system and subsystem. They should develop an understanding of how the parts of a cell interact with one another and how these parts help to do the ‘work’ of the cell (Source: (n.d.). Retrieved from <http://sciencenetlinks.com/lessons/cells-2-the-cell-as- a-system/>) 10 Teacher Tip The review on the differences between prokaryotic and eukaryotic cells is needed to connect prerequisite knowledge to the present lesson. Remind the learners that the cell parts are found in eukaryotic cells. Remind the learners of the pre-topic assignment that shall be submitted before the lecture. This is to ensure the learners read on the topic before the lecture. Briefly discuss the structure of the cell membrane in order to provide basic knowledge on said structure to the learners. Do not fully elaborate on this topic since the structure and function of the cell membrane shall further be discussed in the succeeding parts of the lesson. The cell’s parts should be discussed as a system, emphasizing on the interconnectedness of each part to the others. To clarify common misconceptions, emphasize the following to the learners: • Not all organelles are surrounded by a membrane. • The plasma or cell membrane is different from the cell wall. • Not all cell parts are present in all kinds of cells.
MOTIVATION (5 MINS) Briefly review the differences between prokaryotic and eukaryotic cells by asking questions to the learners. Sample question: What cell parts can be found in both prokaryotic and eukaryotic cells? Discuss the function/s of each part. Sample Responses: • DNA • Cell membrane • Protoplasm (nucleoloid region and cytosol) • Ribosomes Compare the cell to a big city. Ask the learners what the requirements of the city would be in order for it to function. Relate these requirements to the parts of the cell. Relate the learners’ responses to the functions of the different parts of a cell. Sample responses: • The city will need power. What generates power for the city? Relate this to the function of the mitochondria and the chloroplast. • The city generates waste. How does it minimize its waste? How does the city handle its garbage? Relate this to the function of the lysosome. • The city requires raw materials to process into food, clothing, and housing materials. Where are these raw materials processed? Relate this to the functions of the Golgi Apparatus. Compare animal cells from plant cells. For the animal cells, scrape cheek cells using a toothpick. Ask the learners to place the scrapings on a microscope slide and add a drop of water to the scrapings. Tease the scrapings into a thin layer and cover with a slip. Examine under HPO. Instruct the learners to draw the cells on their workbooks and to label the cell parts that they were able to observe under the microscope. For the plant cells, instruct the learners to obtain a Hydrilla leaf and place it on a microscope slide. Examine under LPO. Ask the learners to draw the cells on their workbooks and to label the cell parts that they were able to observe under the microscope.  Teacher tip If the number of available microscopes is limited, ask the learners to group themselves according to the number of microscopes available or set-up a demonstration scope for the whole class and facilitate the examination of cells so that all the learners will get a chance to observe the cells under the microscope. Orient the learners on the proper use and care of the microscopes, particularly on focusing first on LPO before shifting to HPO. Cheek cells are very transparent. Adjust the iris diaphragm or add a small amount of dye (i.e., methylene blue) to the scrapings. The learners will only see the cell membrane and the nucleus. Remind the learners to draw what they observe. Students may observe cytoplasmic streaming in the plant cell.
INSTRUCTION/PRACTICE (30 MINS) 1. Draw the cell membrane on one end of the board. 2. Draw the double membrane of the nucleus (nuclear membrane) on the other end of the board. 3. From the nuclear membrane, draw the reticulated structure of the endoplasmic reticulum. Ask the learners what the two types of endoplasmic reticulum are and their corresponding functions. 4. Draw the ribosomes as separate units. 5. Draw a DNA and an mRNA. Explain that the mRNA is a copy of the DNA that will be sent to the cytoplasm for protein synthesis. 6. Explain to the learners that the mRNA leaves the nucleus and goes to where the ribosomes are located (i.e., mRNA + functional ribosome) 7. Explain the possible ‘pathways’ for protein synthesis (e.g., within the cytosol or the endoplasmic reticulum) 8. Draw the mRNA + functional ribosome on the endoplasmic reticulum. With a lot of these, the endoplasmic reticulum becomes a rough endoplasmic reticulum. 9. Draw the formed polypeptide inside the rough endoplasmic reticulum. Discuss the formation of a cisternae and pinching off as a vesicle. 10. Draw the Golgi Apparatus and then a vesicle from the rough endoplasmic reticulum that travels to the Golgi Apparatus and attaches to the part which is nearest the rough endoplasmic reticulum. 11. Ask the learners what the function of the Golgi Apparatus is. Synthesize their answers and compare the Golgi Apparatus to a factory with an assembly manufacturing line. 12. Draw the polypeptide travelling along the Golgi Apparatus stack; pinching off as a vesicle to travel to the next stack. Repeat the process while increasing the complexity of the polypeptide drawing. 13. On the last stack, explain the ‘pathways’ that the vesicle may follow: become a lysosome through fusion with an endosome (i.e., formed by endocytosis), or travel to the cell membrane, fuse with it, and empty its contents. 14. Present the composition of the endomembrane system and discuss how these parts are connected to each other by structure and by function. 15. Draw the mitochondria and label its parts. Explain the importance of the enfolding (cristae) in increasing the surface area of the inner mitochondrial membrane. Further explain to the class that Teacher tip Use chalk or white board markers with different colors. Explain the structure and function of each cell part as you draw them. Explain to the learners that a more detailed discussion of the structure and functions of the cell membrane, mitochondria, and chloroplast will be given in succeeding lessons.
enfolding is a common structural strategy to increase surface area. As an example, you may draw a cross-sectional structure of the small intestine. 16. Draw the chloroplast and label its parts. Explain the function that each part performs in the process of photosynthesis. 17. Discuss the similarities of the mitochondria and chloroplast (e.g., both are involved in energy transformation, both have DNA, high surface area, and double membranes).income accounts and lastly, expenses accounts.     Group the learners into pairs. Ask one to draw the endomembrane system as he/she explains it to his/her partner. Reshuffle the groupings and repeat until all learners have performed the exercise. ENRICHMENT (30 MINS) Facilitate a class discussion on why cells are generally small in size. Explain the relationship between surface area and volume. EVALUATION (60 MINS Ask questions to the learners. Sample questions can be found in the following electronic resources: • (n.d.). Retrieved from< http://www.proprofs.com/quiz-school/story.php?title=cell-structure-test > • (n.d.). Retrieved from< http://study.com/academy/exam/topic/cell-biology.html> Assign a research assignment on this question: How do environmental toxins like lead and mercury affect the functions of the cell? The assignment shall be submitted one week after this lesson. RESOURCES (CONTINUED): (4) (n.d.). Retrieved from <http://www.schools.manatee.k12.fl.us/072JOCONNOR/celllessonplans/ lesson_plan__cell_structure_and_function.html> (5) (n.d.). Retrieved from <http://www.phschool.com/science/biology_place/biocoach/cells/endo.html> (6) (n.d.). Retrieved from <http://study.com/academy/lesson/the-endomembrane-system-functions- components.html> (7) (n.d.). Retrieved from <http://www.ncbi.nlm.nih.gov/books/NBK26907/> (8) (n.d.). Retrieved from <http://staff.um.edu.mt/acus1/01Compart.pdf>  Teacher tip Assignments should be handwritten. This strategy is aimed at ensuring that the learners have read the topic rather than just copying and printing from a source.
ASSESSMENT 14 Learning Competency Assessment Tool Exemplary Satisfactory Developing Beginnning The learners shall be able to: 1. describe the structure and function of major and subcellular organelles (STEM_BIO11/12-Ia-c-2) Learner participation (during lecture) Learner was able to answer all the question/s without referring to his/ her notes Learner was able to answer the main question without referring to his/her notes but was not able to answer follow-up question/s Learner was able to answer the questions but he/she referred to his/her notes (1) Learner was not able to answer the question/s (2) Learner read notes of his/her classmate Assignment Learner submitted an assignment beyond the requirements Learner submitted a comprehensive and well- written assignment Learner submitted a well written report but some responses lack details (1) Learner did not submit an assignment (2) Learner submitted a partially-finished assignment The learners shall be able to: 2. describe the structural components of the cell membrane (STEM_BIO11/12-Ig-h-11) Learner participation (during practice) Learner was able to concisely answer all the questions Learner was able to answer the main question without referring to his/her notes but was not able to answer follow-up question/s Learner was able to answer the questions but he/she referred to his/her notes (1) Learner was not able to answer the question/s (2) Learner read notes of his/her classmate Laboratory (Examination of Animal and Plant Cells) Learner submitted drawings that were beyond the requirements Learner submitted drawings that fulfilled the requirements (complete and detailed) Learner submitted drawings that were incomplete (1) Learner was not able to submit drawings (2) Learner’s drawings were haphazardly done The learners shall be able to: 3. relate the structure and composition of the cell membrane to its function (STEM_BIO11/12-Ig-h12) Examination Learner obtained 90% to 100% correct answers in the examination Learner obtained 70% to 89.99% correct answers in the examination Learner obtained 50% to 69.99% correct answers in the examination Learner obtained less that 50% correct answers in the examination Research Assignment Learner submitted a research assignment beyond the requirements Learner submitted a comprehensive and well- written research assignment Learner submitted a well written report but some responses lack details (1) Learner did not submit an assignment (2) Learner submitted a partially-finished assignment
General Biology 1 Mitochondria and Chloroplasts Content Standards The learners demonstrate an understanding of the structure and function of the mitochondria and chloroplasts, the organelles involved in energy transformation. Performance Standards The learners shall be able to construct three-dimensional models of whole cells using indigenous or recyclable materials. These models should show the mitochondria and chloroplasts. Learning Competencies The learners describe the structure and function of major and subcellular organelles (STEM_BIO11/12-Ia-c-2) and distinguish prokaryotic and eukaryotic cells according to their distinguishing features (STEM_BIO11/12 -Ia-c-3) Specific Learning Outcomes At the end of the lesson, the learners shall be able to: • illustrate the structure of the mitochondria, label its parts, and understand the importance of the enfolding of the inner mitochondrial membrane • illustrate the structure of the chloroplast, label its parts, and relate these parts to photosynthesis 60 MINS LESSON OUTLINE Introduction Review of relevant terminologies and definitions 5 Motivation Understanding of key concepts using real-life situations 5 Instruction/ Delivery Discussion and lecture proper 30 Practice Drawing (with label) activity 10 Enrichment Computation of surface area vs volume 5 Evaluation Answering practice questions and homework 5 Resources (continued at the end of Teaching Guide) (1) http://scienceaid.co.uk/biology/biochemistry/atp.html (2) http://www.britannica.com/list/6-cell-organelles) (3) http://www.nature.com/scitable/topicpage/mitochondria-14053590) (4) http://www.britannica.com/list/6-cell-organelles (5) http://www.nature.com/scitable/topicpage/mitochondria-14053590) (6) http://biology.tutorvista.com/animal-and-plant-cells/chloroplasts.html (7) ttp://www.nature.com/scitable/topicpage/mitochondria-14053590
INTRODUCTION (5 MINS) Facilitate a review of the following concepts: • Differences between prokaryotic and eukaryotic cells • Definition of an ‘organelle’ • Differences between membrane-bound organelles and non-membrane-bound organelles • Functions of the different parts of a cell • The endomembrane system Explain that in eukaryotic cells, the machinery of the cell is compartmentalized into organelles. The compartmentalization of the cell into membrane-bound organelles: • allows conflicting functions (i.e., synthesis vs. breakdown) and several cellular activities to occur simultaneously without interference from each other • separates the DNA material of the nucleus, mitochondria, and chloroplast • increases the surface area-volume ratio of the cell MEMBRANE-BOUND ORGANELLES NON-MEMBRANE-BOUND ORGANELLES Nucleus Ribosomes Smooth ER Centrioles Rough ER Cytoskeleton Golgi Apparatus Vacuoles and Vesicles Mitochondria Chloroplast and other plastids Lysosomes Peroxisomes 16
Encourage the learners to look at the cell as both a system and subsystem. They should develop an understanding of how the parts of a cell interact with one another and how these parts help to do the ‘work’ of the cell (Source: (n.d.). Retrieved from <http://sciencenetlinks.com/lessons/cells-2-the-cell-as- a-system/>) Emphasize to the learners that energy transformation is one of the characteristics of life. This refers to the ability to obtain and use energy. This characterizes the main function of the mitochondria and the chloroplasts. MOTIVATION (5 MINS) Ask the learners how they understand the concept of compartmentalization. Relate the concept to how the cell is compartmentalized into organelles. Compare compartmentalization to the division of a house into a receiving room or sala, kitchen, dining room, comfort rooms, bedrooms, etc. Ask the learners why they think a house is divided into several rooms. A possible response is that partitioning of the house into different parts facilitates the simultaneous occurrence of several activities without interfering with one another. Also, materials needed for each activity can be stored at their specific areas. For example, pots and pans are being stored in the kitchen and not in the bedroom. Beds and pillows are found in the bedroom and not in the toilet/bath. Explain to the learners that the mitochondria and chloroplasts have a small amount of DNA. Although most of the proteins of these organelles are imported from the cytosol and are thus programmed by the nuclear DNA, their DNA programs the synthesis of the proteins made on the organelles’ ribosomes (Source: Campbell et al). Compartmentalization separates the DNA material of the nucleus, mitochondria, and chloroplast. Ask the learners if they have experienced going to a city/municipal hall and if they have observed that the Mayor, Vice-Mayor, and the City/Municipal Administrator have separate offices. You can use other examples such as the University President, VP for Academic Affairs, VP for Finance; Philippine President, Vice President, Senators, etc. Compare the nuclear DNA to the Mayor and the mitochondrial DNA and chloroplast DNA to the Vice   Teacher tip Explain to the learner that this is how the cell is able to allow conflicting functions (e.g., synthesis vs breakdown) and several cellular activities to occur simultaneously without interference from each other.
Mayor. The Mayor runs the city/municipality but the Vice Mayor also performs functions that are specific to their positions. They need different offices (or compartments) to avoid conflict in their functions. Introduce the concept of surface area-volume ratio/relationship to the learners. Show a fruit to the learners and explain that the outer surface of the fruit is the surface area. Peel the fruit and show them what’s inside, explaining that the inside of the fruit is the volume. Explain to the learners that surface area (SA) and volume (V) do not increase in the same manner. As an object increases in size, its volume increases as the cube of its linear dimensions while surface area increases as the square of its linear dimensions. Example: If the initial starting point is the same: SA = 2; Volume = 2 (Ratio = 1:1) A one-step increase will result to: SA = 22 = 4 while V = 23 = 8 (Ratio = 1:2) INSTRUCTION/DELIVERY (30 MINS) Explain and discuss the nature and functions of the Adenosine Triphosphate (ATP) to the learners. Adenosine Triphosphate (ATP)—It is the major energy currency of the cell that provides the energy for most of the energy-consuming activities of the cell. The ATP regulates many biochemical pathways. Mechanism: When the third phosphate group of ATP is removed by hydrolysis, a substantial amount of free energy is released. ATP + H2O → ADP + Pi where ADP is adenosine diphosphate and Pi is inorganic phosphate Group the learners into pairs. Ask one to draw the endomembrane system as he/she explains it to his/ her partner. Reshuffle the groupings and repeat until all learners have performed the exercise.   18 Teacher tip Select a fruit that can be easily peeled like calamansi or dalandan Teacher tip Ask questions to the learners while giving the lecture. If an LCD projector is not available, draw the structure of the mitochondria and chloroplast on the board.
Illustration 1: Energy release in Hydrolysis (Source: (n.d.). Retrieved from http://scienceaid.co.uk/biology/biochemistry/atp.html) Illustration 2: Chemical Energy and ATP (Source: (n.d.). Retrieved from http://winklebiology.weebly.com/chemical-energyatp.html) Synthesis of ATP • ADP + Pi → ATP + H2O • requires energy: 7.3 kcal/mole • occurs in the cytosol by glycolysis  
• occurs in mitochondria by cellular respiration • occurs in chloroplasts by photosynthesis Consumption of ATP ATP powers most energy-consuming activities of cells, such as: • anabolic (synthesis) reactions, such as: • joining transfer RNAs to amino acids for assembly into proteins • synthesis of nucleoside triphosphates for assembly into DNA and RNA • synthesis of polysaccharides • synthesis of fats • active transport of molecules and ions • conduction of nerve impulses • maintenance of cell volume by osmosis • addition of phosphate groups (phosphorylation) to different proteins (e.g., to alter their activity in cell signaling) • muscle contraction • beating of cilia and flagella (including sperm) • bioluminescence Extracellular ATP In mammals, ATP also functions outside of cells. ATP is released in the following examples: • from damaged cells to elicit inflammation and pain • from the carotid body to signal a shortage of oxygen in the blood • from taste receptor cells to trigger action potentials in the sensory nerves leading back to the brain • from the stretched wall of the urinary bladder to signal when the bladder needs emptying In eukaryotic cells, the mitochondria and chloroplasts are the organelles that convert energy to other forms which cells can use for their functions. Discuss the function and structure of the mitochondria. 20
Mitochondria (singular, mitochondrion)—Mitochondria are the sites of cellular respiration, the metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels. The mitochondria are oval-shaped organelles found in most eukaryotic cells. They are considered to be the ‘powerhouses’ of the cell. As the site of cellular respiration, mitochondria serve to transform molecules such as glucose into an energy molecule known as adenosine triphosphate (ATP). ATP fuels cellular processes by breaking its high-energy chemical bonds. Mitochondria are most plentiful in cells that require significant amounts of energy to function, such as liver and muscle cells. Figure 1: Structure of the Mitochonsdria (Source: (n.d.). Retrieved from http://www.britannica.com/list/ 6-cell-organelles) The mitochondria has two membranes that are similar in composition to the cell membrane: • Outer membrane—is a selectively permeable membrane that surrounds the mitochondria. It is the site of attachment for the respiratory assembly of the electron transport chain and ATP Synthase. It has integral proteins and pores for transporting molecules just like the cell membrane • Inner membrane—folds inward (called cristae) to increase surfaces for cellular metabolism. It contains ribosomes and the DNA of the mitochondria. The inner membrane creates two enclosed spaces within the mitochondria: • intermembrane space between the outer membrane and the inner membrane; and • matrix that is enclosed within the inner membrane. Ask questions to the learners on the structure of the mitochondria. A sample question could be: What is the importance of the enfolding of the mitochondria? The response would be to increase the surface area that can be ‘packed’ into such a small space. Discuss the purpose of the mitochondrial membranes. 22
As mentioned, the mitochondria has two membranes: the outer and inner mitochondrial membranes. • Outer Membrane • fully surrounds the inner membrane, with a small intermembrane space in between • has many protein-based pores that are big enough to allow the passage of ions and molecules as large as a small protein • Inner membrane • has restricted permeability like the plasma membrane • is loaded with proteins involved in electron transport and ATP synthesis • surrounds the mitochondrial matrix, where the citric acid cycle produces the electrons that travel from one protein complex to the next in the inner membrane. At the end of this electron transport chain, the final electron acceptor is oxygen, and this ultimately forms water (H20). At the same time, the electron transport chain produces ATP in a process called oxidative phosphorylation During electron transport, the participating protein complexes push protons from the matrix out to the intermembrane space. This creates a concentration gradient of protons that another protein complex, called ATP synthase, uses to power synthesis of the energy carrier molecule ATP. Figure 4: The Electrochemical Proton Gradient and the ATP Synthase (Source: (n.d.). Retrieved from http://www.nature.com/scitable/topicpage/mitochondria-14053590) Explain and discuss the structure and functions of the Chloroplasts. Chloroplasts—Chloroplasts, which are found in plants and algae, are the sites of photosynthesis. This process converts solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds such as sugars from carbon dioxide and water. The word chloroplast is derived from the Greek word chloros which means ‘green’ and plastes which means ‘the one who forms’. The chloroplasts are cellular organelles of green plants and some eukaryotic organisms. These organelles conduct photosynthesis. They absorb sunlight and convert it into sugar molecules. They also produce free energy stored in the form of ATP and NADPH through photosynthesis. Chloroplasts are double membrane-bound organelles and are the sites of photosynthesis. The   22 Teacher tip Lecture on mitochondrial membranes can be accessed at (n.d.). Retrieved from <http://www.nature.com/scitable/ topicpage/mitochondria-14053590>.
chloroplast has a system of three membranes: the outer membrane, the inner membrane, and the thylakoid system. The outer and the inner membranes of the chloroplast enclose a semi-gel-like fluid known as the stroma. The stroma makes up much of the volume of the chloroplast. The thylakoid system floats in the stroma. Structure of the Chloroplast • Outer membrane—This is a semi-porous membrane and is permeable to small molecules and ions which diffuse easily. The outer membrane is not permeable to larger proteins. • Intermembrane Space—This is usually a thin intermembrane space about 10-20 nanometers and is present between the outer and the inner membrane of the chloroplast. • Inner membrane—The inner membrane of the chloroplast forms a border to the stroma. It regulates passage of materials in and out of the chloroplast. In addition to the regulation activity, fatty acids, lipids and carotenoids are synthesized in the inner chloroplast membrane. • Stroma—This is an alkaline, aqueous fluid that is protein-rich and is present within the inner membrane of the chloroplast. It is the space outside the thylakoid space. The chloroplast DNA, chloroplast ribosomes, thylakoid system, starch granules, and other proteins are found floating around the stroma. • Thylakoid System  The thylakoid system is suspended in the stroma. It is a collection of membranous sacks called thylakoids. Thylakoids are small sacks that are interconnected. The membranes of these thylakoids are the sites for the light reactions of the photosynthesis to take place. The chlorophyll is found in the thylakoids. The thylakoids are arranged in stacks known as grana. Each granum contains around 10-20 thylakoids. The word thylakoid is derived from the Greek word thylakos which means 'sack'. Important protein complexes which carry out the light reaction of photosynthesis are embedded in the membranes of the thylakoids.   The Photosystem I and the Photosystem II are   Teacher tip If an LCD projector is not available, draw the structure of the chloroplast on the board. Lecture on structure and functions of the chloroplast can be accessed at (n.d.). Retrieved from <http:// biology.tutorvista.com/animal-and-plant- cells/chloroplasts.html>.
complexes that harvest light with chlorophyll and carotenoids. They absorb the light energy and use it to energize the electrons. The molecules present in the thylakoid membrane use the electrons that are energized to pump hydrogen ions into the thylakoid space. This decreases the pH and causes it to become acidic in nature. A large protein complex known as the ATP synthase controls the concentration gradient of the hydrogen ions in the thylakoid space to generate ATP energy. The hydrogen ions flow back into the stroma. Thylakoids are of two types: granal thylakoids and stromal thylakoids. Granal thylakoids are arranged in the grana. These circular discs that are about 300-600 nanometers in diameter. The stromal thylakoids are in contact with the stroma and are in the form of helicoid sheets. The granal thylakoids contain only Photosystem II protein complex. This allows them to stack tightly and form many granal layers with granal membrane. This structure increases stability and surface area for the capture of light. The Photosystem I and ATP synthase protein complexes are present in the stroma. These protein complexes act as spacers between the sheets of stromal thylakoids. PRACTICE (10 MINS) Group the learners into pairs. Ask one to draw the mitochondria and label its parts while the other does the same for chloroplast. Once done, the partners exchange tasks (i.e., the learner that drew the mitochondria now does the same for the chloroplast). Reproduce these diagrams without the labels and use these for the class activity. To demonstrate how folding increases surface area, ask the learners to trace the edges of the outer membrane with a thread and measure the length of the thread afterwards. Repeat the same for the inner membrane. Compare the results and discuss how the enfolding of the inner membrane increases surface area through folding. 24
ENRICHMENT (30 MINS)  1. Using the figure below, ask learners to compute surface area vs. volume. 2. Draw the table on the board and instruct the learners to write their measurements. 
EVALUATION (60 MINS) Ask the learners to answer practice questions on the following electronic resources: • http://www.mcqbiology.com/2013/03/multiple-choice-questions-on_25.html#.Vl7Uq3YrLrc • http://www.uic.edu/classes/bios/bios100/summer2004/samples02.htm • http://www.tutorvista.com/content/science/science-i/fundamental-unit-life/question-answers-1.php • http://www.buzzfeed.com/kellyoakes/the-mitochondria-is-the-powerhouse-of-the-cell#.fajAl0b6o • http://global.oup.com/uk/orc/biosciences/cellbiology/wang/student/mcqs/ch10/ Possible responses to the homework (Source: Campbell et al, 10th Ed.): • They have double membranes and are not part of the endomembrane system. • Their shape is changeable. • They are autonomous (somewhat independent) organelles that grow and occasionally pinch in two, thereby reproducing themselves. • They are mobile and move around the cell along tracks of the cytoskeleton, a structural network of the cell. • They contain ribosomes, as well as multiple circular DNA molecules associated with their inner membranes. The DNA in these organelles programs the synthesis of some organelle proteins on ribosomes that have been synthesized and assembled there as well. 2. Give out the homework for next meeting. What are the characteristics shared by these two energy transforming organelles? Instruct the learners to write an essay on probable reasons for these the shared characteristics of the mitochondria and the chloroplast. Learners shall submit a handwritten essay on the Endosymbiotic Theory and how it explains the similarity between the mitochondria and chloroplast. 26 Teacher tip Clarify to the learners the misconception that the appearance of organelles are static and rigid. Teacher tip Check the electronic resources on Endosymbiotic Theory: https://www.youtube.com/watch? v=bBjD4A7R2xU (Endosymbiotic Theory in plain English) https://www.youtube.com/watch?v=- FQmAnmLZtE
EVALUATION Learning Competency Assessment Tool Exemplary Satisfactory Developing Beginnning The learners shall be able to describe the following: 1. structure and function of major and subcellular organelles (STEM_BIO11/12-Ia- c-2) Learner participation (during lecture) Learner was able to answer all the question/ s without referring to his/her notes Learner was able to answer the main question without referring to his/ her notes but was not able to answer follow-up question/s Learner was able to answer the questions but he/ she referred to his/ her notes (1) Learner was not able to answer the question/s (2) Learner read notes of his/her classmate Assignment Learner submitted an assignment beyond the requirements Learner submitted a comprehensive and well- written assignment Learner submitted a well written report but some responses lack details (1) Learner did not submit an assignment (2) Learner submitted a partially-finished assignment Examination Learner obtained 90% to 100% correct answers in the examination Learner obtained 70% to 89.99% correct answers in the examination Learner obtained 50% to 69.99% correct answers in the examination Learner obtained less that 50% correct answers in the examination Essay Assignment Learner submitted an essay beyond the requirements Learner submitted an essay that was comprehensive and well- written Learner submitted a well-written essay some details are lacking (1) Learner did not submit an essay (2) Learner submitted a partially-finished essay
General Biology 1 Mitochondria and Chloroplasts Content Standards The learners demonstrate an understanding of the structure and function of the mitochondria and chloroplasts, the organelles involved in energy transformation. Performance Standards The learners shall be able to construct three-dimensional models of whole cells using indigenous or recyclable materials. These models should show the mitochondria and chloroplasts. Learning Competencies The learners describe the structure and function of major and subcellular organelles (STEM_BIO11/12-Ia-c-2) and distinguish prokaryotic and eukaryotic cells according to their distinguishing features (STEM_BIO11/12 -Ia-c-3) Specific Learning Outcomes At the end of the lesson, the learners shall be able to: • illustrate the structure of the mitochondria, label its parts, and understand the importance of the enfolding of the inner mitochondrial membrane • illustrate the structure of the chloroplast, label its parts, and relate these parts to photosynthesis 60 MINS LESSON OUTLINE Introduction Review of relevant terminologies and definitions 5 Motivation Understanding of key concepts using real-life situations 5 Instruction/ Delivery Discussion and lecture proper 30 Practice Drawing (with label) activity 10 Enrichment Computation of surface area vs volume 5 Evaluation Answering practice questions and homework 5 Resources (continued at the end of Teaching Guide) (1) http://scienceaid.co.uk/biology/biochemistry/atp.html (2) http://www.britannica.com/list/6-cell-organelles) (3) http://www.nature.com/scitable/topicpage/mitochondria-14053590) (4) http://www.britannica.com/list/6-cell-organelles (5) http://www.nature.com/scitable/topicpage/mitochondria-14053590) (6) http://biology.tutorvista.com/animal-and-plant-cells/chloroplasts.html (7) ttp://www.nature.com/scitable/topicpage/mitochondria-14053590
INTRODUCTION (5 MINS) Facilitate a review of the following concepts: • Differences between prokaryotic and eukaryotic cells • Definition of an ‘organelle’ • Differences between membrane-bound organelles and non-membrane-bound organelles • Functions of the different parts of a cell • The endomembrane system Explain that in eukaryotic cells, the machinery of the cell is compartmentalized into organelles. The compartmentalization of the cell into membrane-bound organelles: • allows conflicting functions (i.e., synthesis vs. breakdown) and several cellular activities to occur simultaneously without interference from each other • separates the DNA material of the nucleus, mitochondria, and chloroplast • increases the surface area-volume ratio of the cell MEMBRANE-BOUND ORGANELLES NON-MEMBRANE-BOUND ORGANELLES Nucleus Ribosomes Smooth ER Centrioles Rough ER Cytoskeleton Golgi Apparatus Vacuoles and Vesicles Mitochondria Chloroplast and other plastids Lysosomes Peroxisomes 16
Encourage the learners to look at the cell as both a system and subsystem. They should develop an understanding of how the parts of a cell interact with one another and how these parts help to do the ‘work’ of the cell (Source: (n.d.). Retrieved from <http://sciencenetlinks.com/lessons/cells-2-the-cell-as- a-system/>) Emphasize to the learners that energy transformation is one of the characteristics of life. This refers to the ability to obtain and use energy. This characterizes the main function of the mitochondria and the chloroplasts. MOTIVATION (5 MINS) Ask the learners how they understand the concept of compartmentalization. Relate the concept to how the cell is compartmentalized into organelles. Compare compartmentalization to the division of a house into a receiving room or sala, kitchen, dining room, comfort rooms, bedrooms, etc. Ask the learners why they think a house is divided into several rooms. A possible response is that partitioning of the house into different parts facilitates the simultaneous occurrence of several activities without interfering with one another. Also, materials needed for each activity can be stored at their specific areas. For example, pots and pans are being stored in the kitchen and not in the bedroom. Beds and pillows are found in the bedroom and not in the toilet/bath. Explain to the learners that the mitochondria and chloroplasts have a small amount of DNA. Although most of the proteins of these organelles are imported from the cytosol and are thus programmed by the nuclear DNA, their DNA programs the synthesis of the proteins made on the organelles’ ribosomes (Source: Campbell et al). Compartmentalization separates the DNA material of the nucleus, mitochondria, and chloroplast. Ask the learners if they have experienced going to a city/municipal hall and if they have observed that the Mayor, Vice-Mayor, and the City/Municipal Administrator have separate offices. You can use other examples such as the University President, VP for Academic Affairs, VP for Finance; Philippine President, Vice President, Senators, etc. Compare the nuclear DNA to the Mayor and the mitochondrial DNA and chloroplast DNA to the Vice   Teacher tip Explain to the learner that this is how the cell is able to allow conflicting functions (e.g., synthesis vs breakdown) and several cellular activities to occur simultaneously without interference from each other.
Mayor. The Mayor runs the city/municipality but the Vice Mayor also performs functions that are specific to their positions. They need different offices (or compartments) to avoid conflict in their functions. Introduce the concept of surface area-volume ratio/relationship to the learners. Show a fruit to the learners and explain that the outer surface of the fruit is the surface area. Peel the fruit and show them what’s inside, explaining that the inside of the fruit is the volume. Explain to the learners that surface area (SA) and volume (V) do not increase in the same manner. As an object increases in size, its volume increases as the cube of its linear dimensions while surface area increases as the square of its linear dimensions. Example: If the initial starting point is the same: SA = 2; Volume = 2 (Ratio = 1:1) A one-step increase will result to: SA = 22 = 4 while V = 23 = 8 (Ratio = 1:2) INSTRUCTION/DELIVERY (30 MINS) Explain and discuss the nature and functions of the Adenosine Triphosphate (ATP) to the learners. Adenosine Triphosphate (ATP)—It is the major energy currency of the cell that provides the energy for most of the energy-consuming activities of the cell. The ATP regulates many biochemical pathways. Mechanism: When the third phosphate group of ATP is removed by hydrolysis, a substantial amount of free energy is released. ATP + H2O → ADP + Pi where ADP is adenosine diphosphate and Pi is inorganic phosphate Group the learners into pairs. Ask one to draw the endomembrane system as he/she explains it to his/ her partner. Reshuffle the groupings and repeat until all learners have performed the exercise.   18 Teacher tip Select a fruit that can be easily peeled like calamansi or dalandan Teacher tip Ask questions to the learners while giving the lecture. If an LCD projector is not available, draw the structure of the mitochondria and chloroplast on the board.
Illustration 1: Energy release in Hydrolysis (Source: (n.d.). Retrieved from http://scienceaid.co.uk/biology/biochemistry/atp.html) Illustration 2: Chemical Energy and ATP (Source: (n.d.). Retrieved from http://winklebiology.weebly.com/chemical-energyatp.html) Synthesis of ATP • ADP + Pi → ATP + H2O • requires energy: 7.3 kcal/mole • occurs in the cytosol by glycolysis  
• occurs in mitochondria by cellular respiration • occurs in chloroplasts by photosynthesis Consumption of ATP ATP powers most energy-consuming activities of cells, such as: • anabolic (synthesis) reactions, such as: • joining transfer RNAs to amino acids for assembly into proteins • synthesis of nucleoside triphosphates for assembly into DNA and RNA • synthesis of polysaccharides • synthesis of fats • active transport of molecules and ions • conduction of nerve impulses • maintenance of cell volume by osmosis • addition of phosphate groups (phosphorylation) to different proteins (e.g., to alter their activity in cell signaling) • muscle contraction • beating of cilia and flagella (including sperm) • bioluminescence Extracellular ATP In mammals, ATP also functions outside of cells. ATP is released in the following examples: • from damaged cells to elicit inflammation and pain • from the carotid body to signal a shortage of oxygen in the blood • from taste receptor cells to trigger action potentials in the sensory nerves leading back to the brain • from the stretched wall of the urinary bladder to signal when the bladder needs emptying In eukaryotic cells, the mitochondria and chloroplasts are the organelles that convert energy to other forms which cells can use for their functions. Discuss the function and structure of the mitochondria. 20
Mitochondria (singular, mitochondrion)—Mitochondria are the sites of cellular respiration, the metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels. The mitochondria are oval-shaped organelles found in most eukaryotic cells. They are considered to be the ‘powerhouses’ of the cell. As the site of cellular respiration, mitochondria serve to transform molecules such as glucose into an energy molecule known as adenosine triphosphate (ATP). ATP fuels cellular processes by breaking its high-energy chemical bonds. Mitochondria are most plentiful in cells that require significant amounts of energy to function, such as liver and muscle cells. Figure 1: Structure of the Mitochonsdria (Source: (n.d.). Retrieved from http://www.britannica.com/list/ 6-cell-organelles) The mitochondria has two membranes that are similar in composition to the cell membrane: • Outer membrane—is a selectively permeable membrane that surrounds the mitochondria. It is the site of attachment for the respiratory assembly of the electron transport chain and ATP Synthase. It has integral proteins and pores for transporting molecules just like the cell membrane • Inner membrane—folds inward (called cristae) to increase surfaces for cellular metabolism. It contains ribosomes and the DNA of the mitochondria. The inner membrane creates two enclosed spaces within the mitochondria: • intermembrane space between the outer membrane and the inner membrane; and • matrix that is enclosed within the inner membrane. Ask questions to the learners on the structure of the mitochondria. A sample question could be: What is the importance of the enfolding of the mitochondria? The response would be to increase the surface area that can be ‘packed’ into such a small space. Discuss the purpose of the mitochondrial membranes. 22
As mentioned, the mitochondria has two membranes: the outer and inner mitochondrial membranes. • Outer Membrane • fully surrounds the inner membrane, with a small intermembrane space in between • has many protein-based pores that are big enough to allow the passage of ions and molecules as large as a small protein • Inner membrane • has restricted permeability like the plasma membrane • is loaded with proteins involved in electron transport and ATP synthesis • surrounds the mitochondrial matrix, where the citric acid cycle produces the electrons that travel from one protein complex to the next in the inner membrane. At the end of this electron transport chain, the final electron acceptor is oxygen, and this ultimately forms water (H20). At the same time, the electron transport chain produces ATP in a process called oxidative phosphorylation During electron transport, the participating protein complexes push protons from the matrix out to the intermembrane space. This creates a concentration gradient of protons that another protein complex, called ATP synthase, uses to power synthesis of the energy carrier molecule ATP. Figure 4: The Electrochemical Proton Gradient and the ATP Synthase (Source: (n.d.). Retrieved from http://www.nature.com/scitable/topicpage/mitochondria-14053590) Explain and discuss the structure and functions of the Chloroplasts. Chloroplasts—Chloroplasts, which are found in plants and algae, are the sites of photosynthesis. This process converts solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds such as sugars from carbon dioxide and water. The word chloroplast is derived from the Greek word chloros which means ‘green’ and plastes which means ‘the one who forms’. The chloroplasts are cellular organelles of green plants and some eukaryotic organisms. These organelles conduct photosynthesis. They absorb sunlight and convert it into sugar molecules. They also produce free energy stored in the form of ATP and NADPH through photosynthesis. Chloroplasts are double membrane-bound organelles and are the sites of photosynthesis. The   22 Teacher tip Lecture on mitochondrial membranes can be accessed at (n.d.). Retrieved from <http://www.nature.com/scitable/ topicpage/mitochondria-14053590>.
chloroplast has a system of three membranes: the outer membrane, the inner membrane, and the thylakoid system. The outer and the inner membranes of the chloroplast enclose a semi-gel-like fluid known as the stroma. The stroma makes up much of the volume of the chloroplast. The thylakoid system floats in the stroma. Structure of the Chloroplast • Outer membrane—This is a semi-porous membrane and is permeable to small molecules and ions which diffuse easily. The outer membrane is not permeable to larger proteins. • Intermembrane Space—This is usually a thin intermembrane space about 10-20 nanometers and is present between the outer and the inner membrane of the chloroplast. • Inner membrane—The inner membrane of the chloroplast forms a border to the stroma. It regulates passage of materials in and out of the chloroplast. In addition to the regulation activity, fatty acids, lipids and carotenoids are synthesized in the inner chloroplast membrane. • Stroma—This is an alkaline, aqueous fluid that is protein-rich and is present within the inner membrane of the chloroplast. It is the space outside the thylakoid space. The chloroplast DNA, chloroplast ribosomes, thylakoid system, starch granules, and other proteins are found floating around the stroma. • Thylakoid System  The thylakoid system is suspended in the stroma. It is a collection of membranous sacks called thylakoids. Thylakoids are small sacks that are interconnected. The membranes of these thylakoids are the sites for the light reactions of the photosynthesis to take place. The chlorophyll is found in the thylakoids. The thylakoids are arranged in stacks known as grana. Each granum contains around 10-20 thylakoids. The word thylakoid is derived from the Greek word thylakos which means 'sack'. Important protein complexes which carry out the light reaction of photosynthesis are embedded in the membranes of the thylakoids.   The Photosystem I and the Photosystem II are   Teacher tip If an LCD projector is not available, draw the structure of the chloroplast on the board. Lecture on structure and functions of the chloroplast can be accessed at (n.d.). Retrieved from <http:// biology.tutorvista.com/animal-and-plant- cells/chloroplasts.html>.
complexes that harvest light with chlorophyll and carotenoids. They absorb the light energy and use it to energize the electrons. The molecules present in the thylakoid membrane use the electrons that are energized to pump hydrogen ions into the thylakoid space. This decreases the pH and causes it to become acidic in nature. A large protein complex known as the ATP synthase controls the concentration gradient of the hydrogen ions in the thylakoid space to generate ATP energy. The hydrogen ions flow back into the stroma. Thylakoids are of two types: granal thylakoids and stromal thylakoids. Granal thylakoids are arranged in the grana. These circular discs that are about 300-600 nanometers in diameter. The stromal thylakoids are in contact with the stroma and are in the form of helicoid sheets. The granal thylakoids contain only Photosystem II protein complex. This allows them to stack tightly and form many granal layers with granal membrane. This structure increases stability and surface area for the capture of light. The Photosystem I and ATP synthase protein complexes are present in the stroma. These protein complexes act as spacers between the sheets of stromal thylakoids. PRACTICE (10 MINS) Group the learners into pairs. Ask one to draw the mitochondria and label its parts while the other does the same for chloroplast. Once done, the partners exchange tasks (i.e., the learner that drew the mitochondria now does the same for the chloroplast). Reproduce these diagrams without the labels and use these for the class activity. To demonstrate how folding increases surface area, ask the learners to trace the edges of the outer membrane with a thread and measure the length of the thread afterwards. Repeat the same for the inner membrane. Compare the results and discuss how the enfolding of the inner membrane increases surface area through folding. 24
ENRICHMENT (30 MINS)  1. Using the figure below, ask learners to compute surface area vs. volume. 2. Draw the table on the board and instruct the learners to write their measurements. 
EVALUATION (60 MINS) Ask the learners to answer practice questions on the following electronic resources: • http://www.mcqbiology.com/2013/03/multiple-choice-questions-on_25.html#.Vl7Uq3YrLrc • http://www.uic.edu/classes/bios/bios100/summer2004/samples02.htm • http://www.tutorvista.com/content/science/science-i/fundamental-unit-life/question-answers-1.php • http://www.buzzfeed.com/kellyoakes/the-mitochondria-is-the-powerhouse-of-the-cell#.fajAl0b6o • http://global.oup.com/uk/orc/biosciences/cellbiology/wang/student/mcqs/ch10/ Possible responses to the homework (Source: Campbell et al, 10th Ed.): • They have double membranes and are not part of the endomembrane system. • Their shape is changeable. • They are autonomous (somewhat independent) organelles that grow and occasionally pinch in two, thereby reproducing themselves. • They are mobile and move around the cell along tracks of the cytoskeleton, a structural network of the cell. • They contain ribosomes, as well as multiple circular DNA molecules associated with their inner membranes. The DNA in these organelles programs the synthesis of some organelle proteins on ribosomes that have been synthesized and assembled there as well. 2. Give out the homework for next meeting. What are the characteristics shared by these two energy transforming organelles? Instruct the learners to write an essay on probable reasons for these the shared characteristics of the mitochondria and the chloroplast. Learners shall submit a handwritten essay on the Endosymbiotic Theory and how it explains the similarity between the mitochondria and chloroplast. 26 Teacher tip Clarify to the learners the misconception that the appearance of organelles are static and rigid. Teacher tip Check the electronic resources on Endosymbiotic Theory: https://www.youtube.com/watch? v=bBjD4A7R2xU (Endosymbiotic Theory in plain English) https://www.youtube.com/watch?v=- FQmAnmLZtE
EVALUATION Learning Competency Assessment Tool Exemplary Satisfactory Developing Beginnning The learners shall be able to describe the following: 1. structure and function of major and subcellular organelles (STEM_BIO11/12-Ia- c-2) Learner participation (during lecture) Learner was able to answer all the question/ s without referring to his/her notes Learner was able to answer the main question without referring to his/ her notes but was not able to answer follow-up question/s Learner was able to answer the questions but he/ she referred to his/ her notes (1) Learner was not able to answer the question/s (2) Learner read notes of his/her classmate Assignment Learner submitted an assignment beyond the requirements Learner submitted a comprehensive and well- written assignment Learner submitted a well written report but some responses lack details (1) Learner did not submit an assignment (2) Learner submitted a partially-finished assignment Examination Learner obtained 90% to 100% correct answers in the examination Learner obtained 70% to 89.99% correct answers in the examination Learner obtained 50% to 69.99% correct answers in the examination Learner obtained less that 50% correct answers in the examination Essay Assignment Learner submitted an essay beyond the requirements Learner submitted an essay that was comprehensive and well- written Learner submitted a well-written essay some details are lacking (1) Learner did not submit an essay (2) Learner submitted a partially-finished essay
General Biology 1 Structure and Functions of Animal Tissues and Cell Modification Content Standard The learners demonstrate an understanding of animal tissues and cell modification. Performance Standard The learners shall be able to construct a three-dimensional model of the animal tissue by using recyclable or indigenous materials. Learning Competencies The learners: • classify different cell types (plant/animal tissue) and specify the functions of each (STEM_BIO11/12-Ia-c-4) • describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair) (STEM_BIO11/12-Ia-c-5) Specific Learning Outcomes At the end of the lesson, the learners shall be able to: • present a five-minute report on how the structures of different animal tissues define their function or show a two-minute infomercial about a disease that is caused by animal tissue malfunction; • provide insights, offer constructive feedback, and note areas of improvement on their classmates’ reports or infomercial  28 180 MINS LESSON OUTLINE Introduction Communicating learning objectives to the learners. 5 Motivation Class Activity: Pinoy Henyo Classroom Edition 10 Instruction/ Delivery Review on the Hierarchy of Biological Organisation and PTSF; Lesson on Animal Tissues and on Cell Modfication 95 Practice Class Activity: Reporting on structure and function of animal tissue or showing of infomercial on diseases. 60 Evaluation Class Quiz 10 Materials microscopes, LCD Projector (if available), laptop or computer (if available), manila paper, cartolina, photos, images, or illustrations of different types of tissues, drawing materials (e.g. pens, pencils, paper, color pencils, etc.) Resources (continued at the end of Teaching Guide) (1) Reece JB, U. L., (2010). Campbell Biology 10th. San Francisco (CA).
INTRODUCTION (5 MINS) Introduce the following learning objectives by flashing these on the board: • classify different cell types (plant/animal tissue) and specify the functions of each (STEM_BIO11/12- Ia-c-4) • describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair) (STEM_BIO11/12-Ia-c-5) Ask the learners to work in pairs and write the learning objectives using their own words. MOTIVATION (10 MINS) PINOY HENYO CLASSROOM EDITION Divide the class into two groups. Explain to the learners that instead of having the typical one-on-one Pinoy Henyo, only one representative from each group shall be asked to go to the front and have the mystery word card on his/her forehead. Only three words shall be allowed from the groups: “Oo”, “Hindi”, or “Pwede”. Violation of the rules of the game (e.g., communicating the mystery word to the guesser) shall merit corresponding penalties or disqualification. Assign three representatives per group to guess the mystery words. Each guesser shall be given one minute and 30 seconds. At the end of the activity, ask one or two learners what they think the learning objectives of the lesson will be. Immediately proceed with the Introduction. Teacher tip For this particular lesson, start with the Motivation first (i.e., class activity on Pinoy Henyo Classroom Edition). After the game, proceed to the Introduction by communicating the learning objectives to the learners. For the part when the learners have to state the learning objectives using their own words, ask the learners to face their seatmates and work in pairs. If the learners are more comfortable in stating the learning objectives in Tagalog or In their local dialect, ask them to do so. Teacher tip Prior to this lesson, assign a reading material or chapter for this topic. This shall aid in the facilitation of the class activity. In choosing the mystery words for the game, do not limit yourself with the four types of animal tissues. You may choose terms that describe the tissue type or even body parts wherein the tissues are located. You may also include diseases that are caused by certain malfunctions on the tissues. Make sure to mention the chosen mystery words in the discussion. This shall help the learners to understand the connection of the game with the lesson. Check how the class behaves during the activity. If the learners get rowdy, you may choose to stop the game. Make sure to warn the learners of the consequences first before the start of the activity.
INSTRUCTION/DELIVERY (95 MINS) Facilitate a five-minute review on the Hierarchy of Biological Organization and on the concept of “form fits function”, the unifying theme in Biology. Review on Hierarchy of Biological Organization 1. Discuss that new properties arise with each step upward the hierarchy of life. These are called emergent properties. 2. Ask the class what the levels of biological organization are. The learners should be able to answer this since this is just a review. In case the class does not respond to the question, you may facilitate the discussion by mentioning the first level of the hierarchy. 3. Start with the cell since it is the most basic unit of life that shows all life properties. cells tissue organ organ system multicellular organism Illustrate this by showing photos of the actual hierarchy using animals that are endemic in the Philippines (e.g., pilandok, dugong, and cloud rat). Review on the unifying theme in Biology: “form fits function” 1. Ask the class what the relation of form (structure) to function and vice versa is 2. Ask for examples of versaingit of life that shows all life properthe torpedo shape of the body of dolphins (mammals with fishlike characteristics) and the bone structure and wing shape of birds in relation to flying. 30 Teacher tip Do not use too much time for the review. Just make sure to guide or lead the learners in remembering past lessons. Provide clues if necessary. Teacher tip For the review on “form fits function”, if the class does not respond well, start giving your own examples for the students to figure out this unifying theme. Make sure to relate structure to function. Mention the role of fossils in determining the habits of extinct animals. By doing this, it shall establish a strong connection between form and function and shall give relevance on the study of this connection in Biology. After this, you may now proceed to the new topic on animal tissues.
Facilitate a class activity (i.e., observation of cells under a microscope) to illustrate that animals are made up of cells. This shall be the foundation of the definition of and discussion on animal tissues. The whole activity and discussion shall last for 90 minutes. If microscopes are available for this activity, set up the equipment and the slides that were prepared prior to the activity. Each slide should show one type of tissue (i.e., epithelial tissue, connective tissue, muscle tissue, and nervous tissue). Make sure that the labels are covered because the learners will be asked to name the tissues based on their observations during the discussion. If there are no microscopes available for the activity, prepare cut-out images, photos, or illustrations that show the different types of tissues (i.e., epithelial tissue, connective tissue, muscle tissue, and nervous tissue). Make sure that the images, photos, or illustrations are not labeled because the learners will be asked to name them. Also, do not immediately identify the type of tissue based on the descriptions that you will be presenting to the class. The learners will be asked to identify which among the slides under the microscope or which image, photo, or illustration matches the description of the structure and function that will be given during the discussion. After the class activity, proceed with the actual lecture. If a computer, laptop, or projector is available, show a PowerPoint presentation that shows the description and function of tissues. If there is no available equipment, you may use flash cards or manila paper where description of structure and function of the different tissue types are written down. Ask the learners which among the microscope slides, image, photo, or illustration fits the given information on description and function. After the learners’ responses, you can flash or show the next slide which shall reveal the image of the specimen with the corresponding label or type of tissue. Epithelial Tissue—This type of tissue is commonly seen outside the body as coverings or as linings of organs and cavities. Epithelial tissues are characterized by closely-joined cells with tight junctions (i.e., a type of cell modification). Being tightly packed, tight junctions serve as barriers for pathogens, mechanical injuries, and fluid loss.  Teacher tip If microscopes are available for this activity, allot 20-30 minutes for the observation of cells. If microscopes are not available, allot only 10-15 minutes. Prior to the activity, prepare the slides that will be put under the microscopes. The slides shall contain the different types of tissue. Make sure to focus the slides so that the learners can observe them clearly. Give the learners enough time to observe the specimens and then ask them to draw on their notebooks what they were able to observe under the microscopes. Encourage the learners to write down the description and function of the specific tissue type as you go through the discussion. If microscopes are not available and you have shown photos, images, or illustrations instead, ask the learners to draw them on their notebooks and encourage them to write down the description and function of the specific tissue type as you go through the discussion. Teacher tip Prepare the lecture in such a way that you do not immediately reveal the label of the images or the terms that are being described. The learners should first be asked to identify the images or slides that fit the description of the structures and functions. This will make the students more engaged in the discussion. Always remind the learners to take down notes while you flash information for each tissue type.
Cells that make up epithelial tissues can have distinct arrangements: • cuboidal—for secretion • simple columnar—brick-shaped cells; for secretion and active absorption • simple squamous—plate-like cells; for exchange of material through diffusion • stratified squamous—multilayered and regenerates quickly; for protection • pseudo-stratified columnar—single layer of cells; may just look stacked because of varying height; for lining of respiratory tract; usually lined with cilia (i.e., a type of cell modification that sweeps the mucus). Figure 1: Epithelial Tissue (Source: Reece JB, U. L. (2010). Campbell Biology 10th. San Francisco (CA):.)  32 Teacher tip Take note that the part on cell modifications is incorporated in the discussion on the structure of the respective cells that make up the tissue that is being discussed. Give emphasis on the differences on the features of the cells that make up the tissue type. For examples or illustrations of the different types of tissues, it is better to use an animal that is endemic in the Philippines or in your specific region so that the learners can relate more in the discussion.
Connective Tissue—These tissues are composed of the following: BLOOD —made up of plasma (i.e., liquid extracellular matrix); contains water, salts, and dissolved proteins; erythrocytes that carry oxygen (RBC), leukocytes for defense (WBC), and platelets for blood clotting. CONNECTIVE TISSUE PROPER (CTP)—made up of loose connective tissue that is found in the skin and fibrous connective tissue that is made up of collagenous fibers found in tendons and ligaments. Adipose tissues are also examples of loose connective tissues that store fats which functions to insulate the body and store energy. CARTILAGE —characterized by collagenous fibers embedded in chondroitin sulfate. Chondrocytes are the cells that secrete collagen and chondroitin sulfate. Cartilage functions as cushion between bones. BONE —mineralized connective tissue made by bone-forming cells called osteoblasts which deposit collagen. The matrix of collagen is combined with calcium, magnesium, and phosphate ions to make the bone hard. Blood vessesl and nerves are found at a central canal surrounded by concentric circles of osteons. Figure 2: Connective Tissue (Source: Reece JB, U. L. (2010). Campbell Biology 10th. San Francisco (CA):.)
Muscle Tissue—These tissues are composed of long cells called muscle fibers that allow the body to move voluntary or involuntary. Movement of muscles is a response to signals coming from nerve cells. In vertebrates, these muscles can be categorized into the following: • skeletal—striated; voluntary movements • cardiac—striated with intercalated disk for synchronized heart contraction; involuntary • smooth—not striated; involuntary Figure 3: Muscle Tissue (Source: Reece JB, U. L. (2010). Campbell Biology 10th. San Francisco (CA):.) Nervous Tissue—These tissues are composed of nerve cells called neurons and glial cells that function as support cells. These neurons sense stimuli and transmit electrical signals throughout the animal body. Neurons connect to other neurons to send signals. The dendrite is the part of the neuron that receives impulses from other neurons while the axon is the part where the impulse is transmitted to other neurons. Figure 4: Neurons and Glial Cells (Source: Reece JB, U. L. (2010). Campbell Biology 10th. San Francisco (CA):.) 
PRACTICE (60 MINS) Divide the class into six groups. Four groups will be reporting on Animal Tissues while two groups will be creating an infomercial on diseases caused by the malfunction of tissue types. Each infomercial group shall cover two tissue types. Each group will be given five minutes to report or show their infomercial. At the end of each presentation, facilitate a five-minute critiquing of the presentation. Make sure to get feedbacks from the learners and clarify misconceptions from the reports. The report or the infomercial on diseases shall not be graded. These will be a kind of formative assessment.Group the learners into pairs. Ask one to draw the mitochondria and label its parts while the other does the same for chloroplast. Once done, the partners exchange tasks (i.e., the learner that drew the mitochondria now does the same for the chloroplast). EVALUATION (10 MINS) Ask the learners to group themselves in pairs or in groups of threes. This will allow the learners to discuss and decide among themselves. However, if a learner chooses to do this activity on his or her own, he or she should be allowed to do so. Ask the learners to briefly and clearly answer the following questions: • What is the importance of having a tissue level in the hierarchy of biological organization? (2 points) • What do the varying shapes and arrangement of epithelial tissue suggests? (2 points) • What is the general function of connective tissues? What function is common to all types of connective tissues? (1 point) • Why are there voluntary and involuntary muscle tissue functions? (2 points) • What is the importance of glial cells in nervous tissues? (1 point) • Identify two cell modifications and describe their respective functions. (2 points) Teacher tip Group the learners before starting the lesson. The reporting may be done the day after finishing the discussion on Animal Tissue Structure, Function, and Cell Modification. The reports may be presented using a table which contains columns for tissue type, cell structures that characterize the tissue, part of the body where the tissue is located, function, and importance. Teacher tip Assess if the learners are ready to answer this individually. If they are not yet ready, this activity can be done in pairs or in groups of threes. Make sure that you provide enough time for the group to discuss their responses. Remind the learners to answer briefly and clearly. If you are not comfortable with this time of exam, a multiple-choice type of evaluation may also be prepared. After getting the responses, you may get feedback from the learners to see if all members of each group helped or participated in their small discussions to answer the short quiz. You may ask learners to rate the members of their group.
General Biology 1 Cell Cycle and Cell Division Content Standard The learners demonstrate an understanding of the cell cycle and cell division (i.e., mitosis and meiosis). Performance Standards The learners shall be able to construct a three-dimensional model of the stages or phases involved in the cell cycle using indigenous or recyclable materials. The learners shall put emphasis on the identification of possible errors that may happen during these stages. Learning Competencies The learners: • characterize the phases of the cell cycle and their control points (STEM_BIO11/12- Id-f-6) • describe the stages of mitosis and meiosis given 2n=6 (STEM_BIO11/12-Id-f-7) • discuss crossing over and recombination in meiosis (STEM_BIO11/12-Id-f-8) • explain the significance or applications of mitosis/meiosis (STEM_BIO11/12-Id-f-9) • identify disorders and diseases that result from the malfunction of the cell during the cell cycle (STEM_BIO11/12-Id-f-10) Specific Learning Outcomes • Identify and differentiate the phases of the cell cycle and their control points • describe and differentiate the stages of mitosis and meiosis given 2n=6 • discuss and demonstrate crossing over and recombination in meiosis • explain the significance and applications of mitosis and meiosis • construct a diagram of the various stages of mitosis and meiosis • identify disorders and diseases that result from malfunctions in the cell during the cell cycle  36 90 MINS LESSON OUTLINE Introduction Presentation of a simplified life cycle of a human being or plant 5 Motivation Video presentation of ‘Cell Cycle and Cell Division’ 5 Instruction/ Delivery Lecture-discussion on the cell through the use of a PowerPoint presentation, video, or cell diagram on a Manila paper; Demonstration of the processes inside the cell using model materials (e.g., beads, cords, yarn with different thickness, coins, etc.); or, Summary of learners’ responses to questions regarding the video on ‘Cell Cycle and Cell Division’ 60 Practice Class activities or games such as Amazing Race or Interphase, Mitosis, or Meiosis Puzzle 10 Enrichment Video presentation or introduction on plant and animal gametogenesis; Microscopic examination of an onion root tip 5 Evaluation Written or oral examination 5 Materials photos of the life cycle or stages of eukaryotic organisms, yarns of different thickness, cords, beads, coins, pens Resources (continued at the end of Teaching Guide) (1) Becker, W.M. (2000). The World of the Cell. Addison Wesley Longman Inc., USA (2) Mader, S.S. (2011).Biology 10th Ed. Mac Graw Hill Education, USA.
INTRODUCTION (5 MINS) Introduce a simplified life cycle of a human being or plant. Let the learners identify the changes throughout the different stages and how these organisms grow and develop. Figure 1: Life Cycle of Man and Higher Plants (Source: (n.d.). Retrieved from http:// www.vcbio.science.ru.nl/en/virtuallessons/cellcycle/postmeio/) MOTIVATION (5 MINS) 1. Play the video on ‘Cell Cycle and Cell Division’. This video can be accessed at http:// www.youtube.com/watch?v=Q6ucKWIIFmg.Divide the class into two groups. 2. Show diagrams of cell division in multicellular or eukaryotic organisms to the class. 38 Teacher tip Explain to the learners that these eukaryotic organisms follow a complex sequence of events by which their cells grow and divide. This sequence of events is known as the Cell Cycle. You can show diagrams or illustrations that demonstrate the growth or increase in the number of organisms. Teacher tip You can download the video prior to this session or if internet connection is available during class, you can just make use of the hyperlink to play the video. To access the video through the hyperlink, simply hold the Control (Ctrl) Key on the keyboard and click on the hyperlink. You should ask the learners thought- provoking questions about the video and relate it to the lesson.
INSTRUCTION/DELIVERY (30 MINS) Facilitate a lecture-discussion on the general concepts of cell division. Cell Division—involves the distribution of identical genetic material or DNA to two daughter cells. What is most remarkable is the fidelity with which the DNA is passed along, without dilution or error, from one generation to the next. Cell Division functions in reproduction, growth, and repair. Core Concepts: • All organisms consist of cells and arise from preexisting cells. • Mitosis is the process by which new cells are generated. • Meiosis is the process by which gametes are generated for reproduction. • The Cell Cycle represents all phases in the life of a cell. • DNA replication (S phase) must precede mitosis so that all daughter cells receive the same complement of chromosomes as the parent cell. • The gap phases separate mitosis from S phase. This is the time when molecular signals mediate the switch in cellular activity. • Mitosis involves the separation of copied chromosomes into separate cells. • Unregulated cell division can lead to cancer. • Cell cycle checkpoints normally ensure that DNA replication and mitosis occur only when conditions are favorable and the process is working correctly. • Mutations in genes that encode cell cycle proteins can lead to unregulated growth, resulting in tumor formation and ultimately invasion of cancerous cells to other organs. The Cell Cycle control system is driven by a built-in clock that can be adjusted by external stimuli (i.e., chemical messages). Checkpoint—a critical control point in the Cell Cycle where ‘stop’ and ‘go-ahead’ signals can regulate the cell cycle. • Animal cells have built-in ‘stop’ signals that halt the cell cycles and checkpoints until overridden by ‘go-ahead’ signals. • Three major checkpoints are found in the G1, G2, and M phases of the Cell Cycle. 38 Teacher tip Note the learners’ responses to questions about the video compared to the expected responses. The expected responses are the concepts listed in the Instruction / Delivery part.
The G1 Checkpoint—the Restriction Point • The G1 checkpoint ensures that the cell is large enough to divide and that enough nutrients are available to support the resulting daughter cells. • If a cell receives a ‘go-ahead’ signal at the G1 checkpoint, it will usually continue with the Cell Cycle. • If the cell does not receive the ‘go-ahead’ signal, it will exit the Cell Cycle and switch to a non-dividing state called G0. • Most cells in the human body are in the G0 phase. The G2 Checkpoint—ensures that DNA replication in S phase has been successfully completed. The Metaphase Checkpoint—ensures that all of the chromosomes are attached to the mitotic spindle by a kinetochore. Kinase—a protein which activates or deactivates another protein by phosphorylating them. Kinases give the ‘go-ahead’ signals at the G1 and G2 checkpoints. The kinases that drive these checkpoints must themselves be activated. • The activating molecule is a cyclin, a protein that derives its name from its cyclically fluctuating concentration in the cell. Because of this requirement, these kinases are called cyclin-dependent kinases or CDKs. • Cyclins accumulate during the G1, S, and G2 phases of the Cell Cycle. • By the G2 checkpoint, enough cyclin is available to form MPF complexes (aggregations of CDK and cyclin) which initiate mitosis. • MPF functions by phosphorylating key proteins in the mitotic sequence. • Later in mitosis, MPF switches itself off by initiating a process which leads to the destruction of cyclin. • CDK, the non-cyclin part of MPF, persists in the cell as an inactive form until it associates with new cyclin molecules synthesized during the interphase of the next round of the Cell Cycle. Discuss the stages of mitosis and meiosis. Mitosis (apparent division)—is nuclear division; the process by which the nucleus divides to produce two new nuclei. Mitosis results in two daughter cells that are genetically identical to each other and to the parental cell from which they came. Cytokinesis—is the division of the cytoplasm. Both mitosis and cytokinesis last for around one to two hours. Prophase—is the preparatory stage, During prophase, centrioles move toward opposite sides of the nucleus. 
• The initially indistinct chromosomes begin to condense into visible threads. • Chromosomes first become visible during early prophase as long, thin, and intertwined filaments but by late prophase, chromosomes are more compacted and can be clearly discerned as much shorter and rod-like structures. • As the chromosomes become more distinct, the nucleoli also become more distinct. By the end of prophase, the nucleoli become less distinct, often disappearing altogether. Metaphase—is when chromosomes become arranged so that their centromeres become aligned in one place, halfway between the two spindle poles. The long axes of the chromosomes are 90 degrees to the spindle axis. The plane of alignment is called the metaphase plate. Anaphase—is initiated by the separation of sister chromatids at their junction point at the centromere. The daughter chromosomes then move toward the poles. Telophase—is when daughter chromosomes complete their migration to the poles. The two sets of progeny chromosomes are assembled into two-groups at opposite ends of the cell. The chromosomes uncoil and assume their extended form during interphase. A nuclear membrane then forms around each chromosome group and the spindle microtubules disappear. Soon, the nucleolus reforms. Meiosis—reduces the amount of genetic information. While mitosis in diploid cells produces daughter cells with a full diploid complement, meiosis produces haploid gametes or spores with only one set of chromosomes. During sexual reproduction, gametes combine in fertilization to reconstitute the diploid complement found in parental cells. The process involves two successive divisions of a diploid nucleus. First Meiotic Division The first meiotic division results in reducing the number of chromosomes (reduction division). In most cases, the division is accompanied by cytokinesis. 40 Teacher tip You may show diagrams or a video demonstrating animal and plant mitosis. The video can be accessed at http:// www.vcbio.science.ru.nl/en/virtuallessons/ mitostage/

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