The document discusses cells and their components. It describes that cells are the fundamental unit of life and contain a nucleus that stores genetic information. The development of the microscope allowed scientists like Hooke and Van Leeuwenhoek to discover and observe cells. Key developments included the identification of plant and animal cells and establishing that all living things are made of one or more cells, leading to the cell theory. The document also describes various cell structures like the cell membrane, cell wall, mitochondria and chloroplasts and their functions.
Cell as basic unit of life ppt 88 slidesICHHA PURAK
This Power point presentation describes Cell as basic unit of life. The slides provide information about Discovery of cell,cell theory,number,size,shape and cell types .Differentiates prokaryotic and eukaryotic cell types and point out major differences in plant and animal cell and also about structure and function of cell organelles
Cell as basic unit of life ppt 88 slidesICHHA PURAK
This Power point presentation describes Cell as basic unit of life. The slides provide information about Discovery of cell,cell theory,number,size,shape and cell types .Differentiates prokaryotic and eukaryotic cell types and point out major differences in plant and animal cell and also about structure and function of cell organelles
Biological Classification
This ppt shows the details of biological classification. it gives a brief idea about the five kingdom classification with a detailed description of kingdoms monera, protista and fungi. a detailed description of viruses, viroids, prions and lichens have also been given....
For more details visit my youtube channel: (VIHIRA ACADEMY)
https://www.youtube.com/channel/UCxo06Nj-QWo_7SNvMyDnJCQ?view_as=subscriber
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
Hello readers,
This PPT is about the chapter:- Tissue which is in science class IX
Question Are In The Book Of NCERT
I Hope this will help You...
Thanks....
Plant kingdom (11th Biology) for complete 11th and 12th notes 1999 and for PP...ASM NAFIS BIOLOGY
This is uploaded with videos on YouTube, linked provided bellow
Introduction and thalophyta- https://youtu.be/OtVqgSXwpAo
Bryophyta-https://youtu.be/QlmhYUNKA98
Pteridophyta- https://youtu.be/WjVXHVCN5Fs
Gymnosperm-https://youtu.be/Yy6pNmDoyz8
Angiosperm-https://youtu.be/ZDmYYklBwh4
Still you can comment us on YouTube to get more explanation and better videos.
Biological Classification
This ppt shows the details of biological classification. it gives a brief idea about the five kingdom classification with a detailed description of kingdoms monera, protista and fungi. a detailed description of viruses, viroids, prions and lichens have also been given....
For more details visit my youtube channel: (VIHIRA ACADEMY)
https://www.youtube.com/channel/UCxo06Nj-QWo_7SNvMyDnJCQ?view_as=subscriber
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
Hello readers,
This PPT is about the chapter:- Tissue which is in science class IX
Question Are In The Book Of NCERT
I Hope this will help You...
Thanks....
Plant kingdom (11th Biology) for complete 11th and 12th notes 1999 and for PP...ASM NAFIS BIOLOGY
This is uploaded with videos on YouTube, linked provided bellow
Introduction and thalophyta- https://youtu.be/OtVqgSXwpAo
Bryophyta-https://youtu.be/QlmhYUNKA98
Pteridophyta- https://youtu.be/WjVXHVCN5Fs
Gymnosperm-https://youtu.be/Yy6pNmDoyz8
Angiosperm-https://youtu.be/ZDmYYklBwh4
Still you can comment us on YouTube to get more explanation and better videos.
CELL ORGANELLS
Plasma membrane
Protoplasm
Cell wall
Cell coat
Mitochondria
Endoplasmic reticulum
Golgi bodies
Ribosome
Nucleus
CONCLUSION
REFRENCE
All living organisms on Earth are divided in pieces
called cells. There are smaller pieces to cells that
include proteins and organelles. There are also larger
pieces called tissues and systems. Cells are small
compartments that hold all of the biological
equipment necessary to keep an organism alive and
successful on Earth.
Cell basic unit of life Biology Chapter No 4Sajjad Mirani
This Slide Contain All Basic Terms and Detail Of Cell With Pictures New Course Of Sindh Text Book Board
By Sajjad Hussain Mirani Sindh University Jamshoro
description about cell biology, different types of cell organelles. single bound cell organellle and doubel membrane bound cell organelles, briefy explain different organelles inside the cell
Students will be able to answer the questions;
1. What is the cell theory?
2. What are the types of microscopes?
3. What are the differences between prokaryotes and
eukaryotes?
4. What is the cell specialization and organization?
5. How do substances pass through cells?
NCERT Solutions | Class IX | Science (Biology) | Chapter 15 | Improvement in ...Biswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
NCERT Solutions | Class IX | Science (Biology) | Chapter 7 | Diversity in Liv...Biswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
NCERT Solutions | Class IX | Science (Biology) | Chapter 6 | TissuesBiswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
NCERT Solutions | Class IX | Science (Biology) | Chapter 5 | The Fundamental ...Biswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
He's a pirate (Pirates of the Caribbean) | Let's Play Ukulele | Free e-GuideBiswarup Majumder
"He's a Pirate" is a 2003 track composed by Klaus Badelt and Hans Zimmer for the 2003 Disney film Pirates of the Caribbean: The Curse of the Black Pearl. It is featured on the soundtrack album of the film and is used at the beginning of the credits for the film...
In this "e-Guide" you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your Ukulele following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...
"Alouette" is a popular French-speaking Canadian children's song, commonly thought to be about plucking the feathers from a lark, in retribution for being woken up by its song. Although it is in French, it is well-known among speakers of other languages.
In this "e-Guide" you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your Ukulele following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...
The Godfather Theme | Speak Softly, Love | Let's Play Ukulele | Free e-GuideBiswarup Majumder
"Speak Softly, Love" is a popular song published in 1972, with music by Nino Rota and lyrics by Larry Kusik. The song was first introduced as an instrumental theme in the 1972 film The Godfather that was simply known as "Love Theme from The Godfather".
In this "e-Guide" you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your Ukulele following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...
"Für Elise" is one of Ludwig van Beethoven's most popular compositions. It is usually classified as a bagatelle, but also sometimes referred to as an Albumblatt. The composition was not published during Beethoven's lifetime, having been discovered by Ludwig Nohl 40 years after the composer's death...
In this "e-Guide" you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your Ukulele and Guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Pollination in plants is the process where pollen is transferred from the anther, the male part of a flower, to the stigma, the female part of a flower. Pollen can be transferred to one plant or even a nearby plant so that they can get fertilized and make more flowers. This happens in plants that have flowers called angiosperms.
In this lesson you will learn about :
1) What is Pollination?
2) Types of Pollination
3) Self-Pollination
- Adaptations for Self-Pollination
- Advantages and Disadvantages of Self-Pollination
4) Cross-Pollination
- Adaptations for Cross-Pollination
- Advantages and Disadvantages of Cross-Pollination
5) Agents of Cross-Pollination
- Entomophilous
- Anemophilous
- Hydrophilous
6) Artificial Pollination
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to their environment, and also as objects of romance, ritual, religion, medicine and as a source of food.
In this lesson you will learn about :
1) Flower - Definition & Functions
2) Floral Symmetry
3) Pedicellate & Sessile Flowers
4) Insertion of Floral Leaves on the Thalamus
5) Parts of a Flower
6) Some Important Terms related to Flowers
7) Floral Whorls - Calyx, Corolla, Androecium and Gynoecium
8) Placentation
9) Inflorescenece
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
In biology, tissue is a cellular organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Broadly tissues can be classified into two major groups : Plant tissue and Animal tissue.
In animals, organs are made up of four basic types of tissues - epithelial tissue, connective tissue, muscle tissue and nerve tissue. These tissues have distinctive features and specific functions which combine to form functioning organs.
In this lesson you will learn about different types of animal tissues :
1) Epithelial Tissue
2) Connective Tissue
3) Muscular tissue
4) Neural Tissue
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
In biology, tissue is a cellular organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Broadly tissues can be classified into two major groups : Plant tissue and Animal tissue.
A plant tissue can be defined as a cell or a group of cells dividing, to give rise to large number of cell, which is collectively referred as tissues. They are structurally and functionally similar to these cells. Plants do have a higher level of structure called plant tissue systems. A plant tissue system can be defined as a functional unit, which connects all organs of a plant. Like animal tissue system, plant tissue system is also grouped into various tissues based on their functions.
In this lesson you will learn about :
1) Tissues - "The Teams of Workers"
2) Types of Plant Tissues
3) Plant Tissue Systems
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Locomotion is movement of an organism from one place to another while movements can be performed at any particular space also. Bending of limbs, peristaltic movements, blinking of eye lids etc are some examples of movements. Locomotion is related with movements. Together, our bones, muscles, and joints - along with tendons, ligaments, and cartilage - form our musculoskeletal system and enable us to do everyday physical activities.
In this lesson you will learn about :
1) Functions of Human Skeleton
2) Parts of Skeletal System
3) Bone - Composition, Structure, Classification
4) The Human Skeleton
5) Joints
6) Lever Mechanism
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Biology is the study of life. As humans are living things, we have an natural sense of curiosity and affection towards life and how has come to be.This section of "Introduction to Biology" takes the form of an asynchronous learning trail or link maze which participants seeking knowledge of fundamentals can follow seeking information and enlightenment at their own pace.
In this lesson you will learn about :
1) What is Biology?
2) The Scientific Method
3) Characteristics of Life
4) Levels of Organization
5) Branches of Biology
6) Importance of Biology
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
"Happy Birthday to You" is a song that is traditionally sung to celebrate the anniversary of a person's birth...
In this e Guide you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...☺️☺️☺️
"Pussy Cat, Pussy Cat" is a popular English language nursery rhyme...
In this e Guide you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...☺️☺️☺️
"Jingle Bells" is one of the best-known and commonly sung American songs in the world. It was written by James Lord Pierpont and published under the title "One Horse Open Sleigh" in the autumn of 1857...
In this e Guide you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song (Full Version)...You can easily play the song (Lead & Accompaniment) in your guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...☺️☺️☺️
"Jingle Bells" is one of the best-known and commonly sung American songs in the world. It was written by James Lord Pierpont and published under the title "One Horse Open Sleigh" in the autumn of 1857...
In this e Guide you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song (Easy Version)...You can easily play the song (Lead & Accompaniment) in your guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...☺️☺️☺️
Frère Jacques is a nursery rhyme of French origin (English: "Are You Sleeping"). The song is about a friar who has overslept and is urged to wake up and sound the bell for the matins, the midnight or very early morning prayers for which a monk would be expected to wake...
In this e Guide you will find "Complete TAB & Staff Notation" + "Chord Progression & Chord Diagram" of this song...You can easily play the song (Lead & Accompaniment) in your guitar following the Notation and Chord Progression...
All my documents are totally free...Please Like and share my documents if you think these documents will help you...Thanks...☺️☺️☺️
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
2. What is a Cell ?
The cell is the fundamental structural and
functional unit of all living beings.
All living things are made of one or more cells.
Every cell has its own life.
Old and weak cells in the body continually die and
are replaced by new cells.
All organisms including ourselves, start life as a
single cell called the zygote.
Cells are so small (microscopic) that they cannot
be seen with the naked eye.
Biswarup Majumder | Bio-World 1
3. The Invention of the Microscope
Biswarup Majumder | Bio-World
The first microscope was constructed by Dutch
scientist Antonie Van Leeuwenhoek (1632-1723).
All his microscopes consisted of a single biconvex
lens and were called simple microscopes.
Some of these microscopes had a considerable
magnifying power up to 200 times.
Lens
Sample
Holder
Focus
Knob
Antonie Van Leeuwenhoek
Leeuwenhoek’s Simple
Microscope
2
4. The Discovery of Cell
Biswarup Majumder | Bio-World
Robert Hooke (1635-1703), an English scientist,
develop a microscope by using two lenses for
achieving greater magnification. Such microscopes
were later known as compound microscopes.
Hooke examined a thin slice of cork (the dead cells
of oak bark) under his microscope. He noted small
geometric shapes which he named cells because
they reminded him of the small room monks lived
in at a monastery.
Robert Hooke
Drawing by Hooke
Hooke’s Microscope
3
5. An Ordinary Compound Microscope
Biswarup Majumder | Bio-World
The ordinary compound microscope of today is
greatly improved design of the original Hooke’s
microscope.
4
6. Electron Microscope
Biswarup Majumder | Bio-World
An electron microscope is a microscope that uses a
beam of accelerated electrons as a source of
illumination.
Electron Microscopes can have magnifications
of ×500000.
Ernst Ruska and Max Knoll built the first electron
microscope in 1931. For this and subsequent work
on the subject, Ernst Ruska was awarded the
Nobel Prize for Physics in 1986.
Pollen Grain
5
7. Light vs. Electron Microscope
Biswarup Majumder | Bio-World
Electron Microscope
Light Microscope
6
8. Cell Theory
Biswarup Majumder | Bio-World
The three Basic Components of the Cell Theory :
1. All organisms are composed of one or more
cells [Schleiden & Schwann (1838-39)].
2. The cell is the basic unit of life in all living
things [Schleiden & Schwann (1838-39)].
3. All cells are produced by the division of
preexisting cells.[Virchow (1858)].
Matthias Schleiden Theodor Schwann
Rudolf Virchow
7
9. Biswarup Majumder | Bio-World
Cells – How Numerous ?
Cells – How Small ?
Mycoplasma gallicepticum, a parasitic bacterium which lives
in the primate bladder, waste disposal organs, genital, and
respiratory tracts, is thought to be the smallest known
organism capable of independent growth and reproduction.
The largest cell found in nature is an Ostrich Egg.
Nerve cells are the longest cell. The longest of nerve cells
in any species are be found in the colossal squid, with some
nerve cells estimated to be over 10 meters in length.
Unicellular Organisms Multicellular Organisms
8
Did You Know ?
10. Biswarup Majumder | Bio-World
Why are cells so small ?
Small cell size is a practical necessity arising from the
decrease in the surface area-to-volume ratio of any
object as it increases in size. As an object increases in
volume, its surface area also increases, but not as
quickly.
This phenomenon has biological significance for two
reasons:
1. The volume of a cell determines the amount of
metabolic activity it carries out per unit of time.
2. The surface area of a cell determines the amount
of substances that can enter it from the outside
environment, and the amount of waste products
that can exit to the environment.
9
14. Biswarup Majumder | Bio-World
Cell Wall
Cell wall is a tough, rigid layer that surrounds some types
of cells. It is located outside the cell membrane whose
main function is to provide rigidity, strength, protection
against mechanical stress and infection.
Cell wall is a characteristic feature to cells of plants,
bacteria, fungi, many algae and some archaea. Protozoans
and animals do not have a cell wall.
The composition of the cell wall differs from one species
to the other.
The Archean cell wall is made of glycoproteins and
polysaccharides. In fungi cell walls are made of
glucosamine and chitin. In algae it is composed of
glycoproteins and polysaccharides. The plant cell wall is
mainly composed of cellulose, hemicellulose, glycoproteins,
pectins and lignin.
Freely permeable and non-living in nature.
The cell wall is like a fort; it
protects the organelles inside
the cell, and provides strength
and support.
13
15. Biswarup Majumder | Bio-World
Plant Cell Wall
The middle lamella - It is first layer formed during cell
division. This layer is rich in pectin. It is the outermost
layer, joins together adjacent plant cells and holds
them together.
The primary cell wall - It is formed after the
middle lamella. It is composed of pectin compounds,
hemicellulose and glycoproteins. The layer consists of a
framework of cellulose micro-fibrils, in a gel-like
matrix. It is thin, flexible and extensible layer.
The secondary cell wall - It is a thick layer formed
inside the primary cell wall. It is extremely rigid and
provides strength. It is composed of cellulose,
hemicellulose and lignin.
14
Plant cell wall consists of three layers : the primary cell
wall, secondary cell wall and the middle lamella.
16. Bacterial cell wall :
The gram positive bacteria have a thick cell wall and is made up of many layers of
peptidoglycan and teichoic acids.
Biswarup Majumder | Bio-World
Bacterial & Fungal Cell Wall
The gram negative bacteria have thinner cell walls, and is made up of few layers of
peptidoglycans and is surrounded by a lipid membrane containing lipopolysacccharides and
lipoproteins.
Made up of peptidoglycans also known as murein. The
cell wall of bacteria is essential for the survival of
bacteria.
Cell wall of bacteria is broadly classified into two types:
gram positive and gram negative.
Fungi cell wall consists of chitin and other polysaccharides.
Species of fungi that possess a cell wall have a plasma
membrane and three layers of cell wall material surrounding
it. These layers are made up of chitin, glucans and a layer a
of mannoproteins (mannose containing glycoproteins).
Fungal cell wall :
15
17. Biswarup Majumder | Bio-World
Cell Wall - Functions
1. Gives the cell a definite shape and structure.
2. Provides structural support.
3. Protection against infection and mechanical stress.
4. Separates interior of the cell from the outer environment.
5. It enables transport of substances and information from
the cell insides to the exterior and vice versa.
6. Also helps in osmotic-regulation.
7. Prevents water loss.
8. The physiological and biochemical activity of the cell wall
helps in cell-cell communication.
9. It prevents the cell from rupturing due to turgor
pressure.
10. Aids in diffusion of gases in and out of the cell.
Plasmodesmata : The Bridge To Somewhere
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18. Biswarup Majumder | Bio-World
Cell Membrane
It is the boundary, which separates the living cell from
their non-living surroundings.
In animal cells, the plasma membrane is present in the
outer most layer of the cell and in plant cell it is present
just beneath the cell wall.
Very thin, flexible, living membrane, possesses fine pores.
Composed of two layers of phospholipids and embedded
with proteins.
It is a thin semi permeable membrane layer, which
allows only selected molecules to diffuse across the
membrane.
Membrane Transport
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19. Biswarup Majumder | Bio-World
Cell Membrane
Structure :
1. Separates contents of the cell from its surroundings.
2. Regulates the entry of certain solutes and ions.
3. Maintain the shape of the cell (in animal cell).
Chief Functions :
It is the phospholipids bilayer.
Plasma membrane is an amphipathic, which contains both
hydrophilic heads and hydrophobic tails.
It is a fluid mosaic of lipids, proteins and carbohydrate.
It is lipid bilayer, which contains - two layers of
phospholipids, phosphate head is polar (water loving),
fatty acid tails non-polar (water fearing) and the
proteins embedded in membrane.
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Fluid mosaic model of a cell membrane by SJ Singer and GL Nicolson in 1972
20. Biswarup Majumder | Bio-World
Cell Wall vs. Cell Membrane
Cell Wall Cell Membrane
It is a rigid, thick structure
and visible in light
microscope.
It is delicate, thin structure
and visible only in electron
microscope.
It is outermost layer in plant
cell and occurs as a
protective covering
surrounding the plasma
membrane.
It is the outermost layer in
animal cell and occurs as a
semi-permeable covering
surrounding the protoplasm.
Cell wall is made up of
cellulose in plant cell.
Cell wall is made up of
peptidoglycan in bacteria.
Cell wall is made up of chitin
in fungi.
Plasma membrane is made up
of lipids, proteins and small
amount of carbohydrates.
It is completely permeable to
ordinary macromolecule.
It is selectively permeable
i.e. allowing only certain
molecules to pass.
It occurs in plant cell,
bacterium and fungus.
It occurs in all cells.
It is metabolically inactive
and non-living.
It is metabolically active and
living.
It determines the cell shape
and offers protection.
It protects protoplasm and
maintains a constant internal
environment to the
protoplasm.
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22. Biswarup Majumder | Bio-World
Protoplasm
✓ The living component of a cell.
✓ Protoplasm = Cytoplasm + Nucleus.
✓ Surrounded by the plasma membrane.
✓ Plant cells have an outer boundary called the cell wall.
Cytoplasm
✓ Jelly like substance enclosed by cell membrane.
✓ Contains organelles to carry out specific jobs.
✓ Provides a medium for chemical reactions to take place.
Nucleus
✓ The cell nucleus acts like the brain of the cell.
✓ Contains genetic material.
Components
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24. Biswarup Majumder | Bio-World
Structure of Nucleus
Nuclear Envelope
▪ It is a double-layered membrane that encloses the
contents of the nucleus during most of the cell’s
lifecycle.
Nuclear Pores
▪ The nuclear envelope is perforated with holes called
nuclear pores.
▪ These pores regulate the passage of molecules between
the nucleus and cytoplasm, permitting some to pass
through the membrane, but not others.
Nucleoplasm
▪ Also called nuclear sap or karyoplasm, is the fluid
usually found in the nucleus of eukaryotic cells.
▪ The fluid contains primarily water, dissolved ions, and a
complex mixture of molecules.
▪ Its primary function is to act as a suspension medium
for the organelles of the nucleus.
Nucleolus
▪ The nucleolus is a membrane-less organelle within the
nucleus that manufactures ribosome, the cell’s protein-
producing structures.
Chromatin
▪ Fibres of DNA and protein, stores information for
synthesis of proteins.
▪ When cell prepares to divide, chromatin fibres coil up
as separate structures, chromosomes.
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25. Biswarup Majumder | Bio-World
Nucleus
▪ It regulates and coordinates various life processes of
the cell.
▪ It plays an important part in cell division.
▪ It contains factors (genes) which determine heredity.
Structure
Chief Functions :
The nucleus is called the "brain” of the cell because it holds the
information needed to conduct most of the cell's functions.
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26. Biswarup Majumder | Bio-World
A gene is the
basic physical and
functional unit of
heredity. Genes,
which are made up
of DNA, act as
instructions to
make molecules
called proteins.
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27. Chromosome Number
Biswarup Majumder | Bio-World
Like the fingerprints, the DNA pattern helps in ascertaining the identify of a
person and hence the term DNA fingerprinting. The technique can even
testify the percentage of an individual. In a woman’s murder case in Delhi in
July 1995 the DNA from her unidentifiable charred dead body was matched
with the DNA from the body cells of her parents to confirm that they really
were the father and mother of the murdered woman. That was one of the
earliest cases. Now, DNA fingerprinting has become very common.
DNA - Fingerprinting
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30. Mitochondria - Structure
Biswarup Majumder | Bio-World
Outer membrane
▪ It is smooth and is composed of equal amounts of
phospholipids and proteins.
▪ It has a large number of special proteins known as
the porins.
▪ The porins are integral membrane proteins and they
allow the movement of molecules that are of 5000
daltons or less in weight to pass through it.
▪ The outer membrane is freely permeable to nutrient
molecules,ions, energy molecules like the ATP and
ADP molecules.
Inner membrane
▪ The inner membrane of mitochondria is more
complex in structure.
▪ It is folded into a number of folds many times and is
known as the cristae.
▪ This folding help to increase the surface area inside
the organelle.
▪ The cristae and the proteins of the inner membrane
aids in the production of ATP molecules.
▪ Various chemical reactions takes place in the inner
membrane of the mitochondria.
▪ Unlike the outer membrane, the inner membrane is
strictly permeable, it is permeable only to oxygen,
ATP and it also helps in regulating transfer of
metabolites across the membrane.
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31. Mitochondria - Structure
Biswarup Majumder | Bio-World
Intermembrane space
▪ It is the space between the outer and inner
membrane of the mitochondria, it has the same
composition as that of the cell's cytoplasm.
▪ There is a difference in the protein content in the
intermembrane space.
Matrix
▪ The matrix of the mitochondria is a complex
mixture of proteins and enzymes. These enzymes
are important for the synthesis of ATP molecules,
mitochondrial ribosomes, tRNAs and mitochondrial
DNA.
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32. Mitochondria - Functions
Biswarup Majumder | Bio-World
The most important function of the mitochondria is to
produce energy. The simpler molecules of nutrition are
sent to the mitochondria to be processed and to produce
charged molecules. These charged molecules combine with
oxygen and produce ATP molecules. This process is known
as oxidative phosphorylation.
Mitochondria help the cells to maintain proper
concentration of calcium ions within the compartments of
the cell.
The mitochondria also help in building certain parts of
blood and hormones like testosterone and estrogen.
The liver cells mitochondria have enzymes that detoxify
ammonia.
The mitochondria also play important role in the process of
apoptosis or programmed cell death. Abnormal death of
cells due to the dysfunction of mitochondria can affect
the function of organ.
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Cellular
Respiration
33. Plastid - Types
Biswarup Majumder | Bio-World
Chloroplasts are elongated disc shaped organelles which contains
chlorophyll. Chlorophyll is present in green plants which helps
them make food by the process of photosynthesis, which uses
energy from the sunlight is converted into chemical energy.
Chromoplasts are plastids which are found in fruits and are
yellow, orange and red in color.
Lecuoplasts are colorless plastids. They found in roots, seeds and
underground stems.
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34. Chloroplast - Structure
Biswarup Majumder | Bio-World
They have a double membrane structure.
They have their own DNA (circular and naked) and ribosomes
(70S).
Thylakoids – flattened discs have a small internal volume to
maximise hydrogen gradient upon proton accumulation
Grana – thylakoids are arranged into stacks to increase SA:Vol
ratio of the thylakoid membrane
Photosystems – pigments organised into photosystems in
thylakoid membrane to maximise light absorption.
Stroma – central cavity that contains appropriate enzymes and
a suitable pH for the Calvin cycle to occur.
Lamellae – connects and separates thylakoid stacks (grana),
maximising photosynthetic efficiency.
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35. The Endosymbiotic Theory
Biswarup Majumder | Bio-World 34
Endosymbiosis (Greek: endon = "within", sym =
"together" and biosis = "living").
An endosymbiont is any organism that lives within the
body or cells of another organism.
The endosymbiosis theory attempts to explain the
origins of organelles such as mitochondria and
chloroplasts in eukaryotic cells.
According to Endosymbiosis theory :
Modern eukaryotic cells evolved from simple, phagotrophic
cells that ingested bacteria and cyanobacteria; the prey was
not digested, and physiological processes of the
endosymbionts were used by the host.
36. Endoplasmic Reticulum
Biswarup Majumder | Bio-World
The endoplasmic reticulum (ER) is a network of
interconnecting membranes distributed throughout the
cytoplasm.
The internal compartment, called the lumen, is a separate
part of the cell with a distinct protein and ion composition.
At certain sites, the ER membrane is continuous with the
outer nuclear envelope membrane.
Depending upon the presence or absence of ribosomes on
the surface, there are two types of E.R.
1. Rough E.R. – presence of ribosomes on its surface.
2. Smooth E.R. – devoid of ribosomes on its surface.
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Structure :
38. Golgi apparatus was discovered in the year 1898 by an
Italian biologist Camillo Golgi.
In plant cells, the Golgi apparatus is called dictyosome.
It is located in the cytoplasm next to the endoplasmic
reticulum and near the cell nucleus.
Golgi Apparatus
Biswarup Majumder | Bio-World 37
Structure :
The Golgi apparatus organelle consists of three
membranous components that can be clearly identified
through the electron microscope. These are lamellae or
cisternae, vesicles and vacuoles.
The flat sacs of the cisternae are stacked and is bent
and semicircular in shape.
The Golgi complex is polar in nature : One end of the
stack is known as the cis face, it is the 'receiving
department" while the other end is the trans face and is
the "shipping department“.
Vesicles are minute spherical structures of the Golgi
apparatus that originate from cisternae by budding or
“pinching off” process. They are found singly or in
clusters.
Vacuoles are spherical, comparatively larger secretory
granules adjacent to cisternae. They also lie at maturing
face and contain electron-dense material.
A Golgi Body is like a “Post Office” because a Post Office
collects and packages packages just like how a Golgi Body
modifies, collects and packages.
39. Golgi Apparatus
Biswarup Majumder | Bio-World 38
The principal function of golgi apparatus organelle is
secretion that occurs in the form of secretory granules.I
t also has a role in neurosecretion secreting
neurosecretory materials.
The golgi apparatus organelle acts as a packaging
organelle and transports various materials like proteins,
polysaccharides out of the cell.
The golgi apparatus takes part in the formation of plasma
membrane, cell wall, lysosomes (primary lysosomes),
acrosome (head cap) of sperm.
Functions :
Structure
40. Lysosome
Biswarup Majumder | Bio-World 39
The cytoplasm of both plant and animal cells contain
many tiny regular shaped membrane bound vesicles
known as lysosomes.
They contain various (at least 50 types) hydrolytic
enzymes.
Lysosomes of injured or dead cells rupture together
and release enzymes which lyse the useless cells.
These are membranous sacs budded off from Golgi
apparatus.
Lysosomes help in digestion. Lysosomes can digest the entire cell
.This takes place during formation of human appendages and
during natural death of cells. Hence it is termed as "Suicidal
bag“.
41. Lysosome - Types
Biswarup Majumder | Bio-World 40
Primary lysosomes: The newly produced lysosomes are
called primary lysosomes ,which is a virgin particle in that
its digestive enzymes have not yet taken part in hydrolysis.
Secondary lysosomes: The lysosomes that is formed by
fusion of primary lysosome and phagosomes is termed
secondary lysosomes.They are of two types - Hetero
Phagosomes are secondary lysosomes formed by
endocytosed phagosomes and primary lysosomes. Lysogenic
digestion of endocytosed material is
termed heterophagy. Auto phagosomes are formed by
fusion of cellular particles and primary lysosomes.The
process of digestion of portion of a cell's own cytoplasmic
constituents by its lysosomes is termed autophagy.
Residual bodies: Hetero Phagosomes and auto phagosomes
after digestion and absorption are left with only residues
and denatured enzymes within the vacuole ,which are
termed residual bodies.
On the basis of function of lysosomes ,they are
classified into three types :
42. Biswarup Majumder | Bio-World 41
Endomemebrane System
Divides cell into compartments.
Includes :
Endoplasmic Reticulum (and vesicles).
Golgi Apparatus (and vesicles).
Lysosomes.
Vacuoles.
Responsible for production of various macromolecules,
including proteins and some lipids.
Important note : The endomembrane system does not
include mitochondria, chloroplasts, or peroxisomes.
43. Ribosomes contain equal amount of proteins and rRNA. So
they are also known as ribonucleoprotein.
Ribosomes functions in two cytoplasmic locations.
Free Ribosomes : They are suspended in the cytoplasm.
Bound Ribosomes : They are attached to the outside of the
endoplasmic reticulum.
Each ribosome has two subunits.
The ribosomes of prokaryotes are smaller than eukaryotes.
They are different in their molecular composition.
Ribosome
Biswarup Majumder | Bio-World 42
44. Ribosome - Function
Biswarup Majumder | Bio-World
The ribosome plays a key role in translating the genetic
message. This genetic message is carried by mRNA from
the nucleus to the cytoplasm. This message is translated in
the ribosomes. It forms specific primary structure (amino
acid sequence) of a polypeptide chain.
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45. Centrosome
Biswarup Majumder | Bio-World
The centrosome is an organelle made up of two mutually
perpendicular structures known as centrioles.
Each centriole is composed of 9 equally spaced peripheral
fibrils of tubulin protein and the fibril is a set of
interlinked triplets. The core part of the centriole is known
as a hub and is proteinaceous in nature. The hub connects
the peripheral fibrils via radial spoke which is made up of
proteins.
The centrioles form spindle fibers during cell division.
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(a) How centrioles are a component
of centrosomes.
(b) How centrosomes are involved in
cell division.
(c) Ultrastructure of centrioles as
seen in T.S.
(C)
47. Vacuoles
Biswarup Majumder | Bio-World
The term “Vacuole” literally means empty space.
Vacuoles are formed by the fusion of small multiple
membrane vesicles.
They have no basic shape or size, and their structure
varies according to needs of cell.
Plant and fungal cells usually consist of large vacuoles
although there number is less, on the contrary animal and
bacterial cells might contain large number of small
vacuoles.
Tonoplast a term commonly associated with vacuoles
refers to a very active and dynamic membrane that
surrounds the plant cell vacuole.
Functions
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49. Cytoplasmic Inclusions
Biswarup Majumder | Bio-World
Types
These are diverse intracellular non-living substances
that are not able to carry out any metabolic activity
and are not bound by membranes.
These structures were first observed by O. F. Müller in
1786.
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