This document provides information about cell structure and function from a student's self-learning material. It discusses the variation in number, shape, and size of cells and describes the structure of a generalized cell, including the cell membrane, cytoplasm, nucleus, and various organelles. It compares the structures of plant and animal cells and explains cell division and growth. The key points covered are that cells are the basic structural and functional units of life, they vary in number, shape, and size, and all cells have a basic structure including a cell membrane, cytoplasm, and nucleus despite differences.
Topic: Table of Specification
Student Name: Shoaib
Class: M.Ed
Project Name: “Young Teachers' Professional Development (TPD)"
"Project Founder: Prof. Dr. Amjad Ali Arain
Faculty of Education, University of Sindh, Pakistan
Current Issues in Education - Meeting the Challenges of the 21st Century Todaypolchan
Current Issues in Education - Meeting the Challenges of the 21st Century Today, a Powerpoint presentation for the subject Current Issues in Education, Graduate Studies.
Topic: Table of Specification
Student Name: Shoaib
Class: M.Ed
Project Name: “Young Teachers' Professional Development (TPD)"
"Project Founder: Prof. Dr. Amjad Ali Arain
Faculty of Education, University of Sindh, Pakistan
Current Issues in Education - Meeting the Challenges of the 21st Century Todaypolchan
Current Issues in Education - Meeting the Challenges of the 21st Century Today, a Powerpoint presentation for the subject Current Issues in Education, Graduate Studies.
Topic: Measurment, Assessment and Evaluation
Student Name: Amna Samo
Class: B.Ed. Hons Elementary Part (II)
Project Name: “Young Teachers' Professional Development (TPD)"
"Project Founder: Prof. Dr. Amjad Ali Arain
Faculty of Education, University of Sindh, Pakistan
A presentation by Rachel Stubley of the School of Education and Centre for Excellence in Learning and Teaching at the University of Wales, Newport, as part of the PGCert Developing Professional Practice in Higher Education, on 2nd December 2009.
Different types of Test
Why do We give tests?
Kinds of tests
Other categories of tests
Two Types of Test (Questions)
Subjective Test Samples
Essay
Types of Essay Items
Matching type
Completion Type
All students including those with different kinds of disabilities
Special children should get all the benefits like normal children, involved in academic and non-academic activities.
Topic: Measurment, Assessment and Evaluation
Student Name: Amna Samo
Class: B.Ed. Hons Elementary Part (II)
Project Name: “Young Teachers' Professional Development (TPD)"
"Project Founder: Prof. Dr. Amjad Ali Arain
Faculty of Education, University of Sindh, Pakistan
A presentation by Rachel Stubley of the School of Education and Centre for Excellence in Learning and Teaching at the University of Wales, Newport, as part of the PGCert Developing Professional Practice in Higher Education, on 2nd December 2009.
Different types of Test
Why do We give tests?
Kinds of tests
Other categories of tests
Two Types of Test (Questions)
Subjective Test Samples
Essay
Types of Essay Items
Matching type
Completion Type
All students including those with different kinds of disabilities
Special children should get all the benefits like normal children, involved in academic and non-academic activities.
A Study of the Effectiveness of Self-Instructional Material (SIM) for Higher ...RHIMRJ Journal
The present study was aimed to find the effectiveness of Self-instructional Materials (SIM). Comparison of the
increased learning through SIM and through Direct Teaching was done in this study to know about the effectiveness of SIM at
Higher Education. The results did not show significant difference between two groups’ learning outcomes. However, various
factors are involved in learning activity. Factors like students’ attention, effectiveness of direct teaching etc. do affect the level
of learning. So, depending upon the above factors and quality of Self-instructional Material, the level of learning may differ.
Next Step Test Prep offers tips and study strategies for your GRE test preparation. If you need extra help with your GRE preparation Next Step can provide a GRE prep online tutor.
http://nextsteptestprep.com/tests/gre-tutors/
Lessons from the Frontier of Courseware DevelopmentDani Nicholson
This is a presentation I did last week (6/16/16) at the New Media Consortium (NMC) summer conference: The number of ed tech startups and the significant investment in adaptive courseware solutions can remind people of the 1860s gold rush: some prospered, but many failed. In the past two years of developing OpenStax Tutor, the OpenStax team has learned several valuable lessons that can benefit educators, digital courseware providers, and students from making costly miscalculations. Lessons learned and presented are 1) technology with high-quality content and assessment is most valuable; 2) instructor workflow is a highway, not a fork in the road; 3) emergence of data privacy standards can accelerate acceptance of digital courseware; and, 4) it's not about price, it's about value.
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
CBSE Class 8 / VIII General Ccience Power Point Presentation
Prepared By
Praveen M Jigajinni
DCSc & Engg,PGDCA,ADCA,MCA,MSc(IT),MTech(IT), M.Phil (Comp Sci)
For Any Queries Please feel free to contact:
Email Id : praveenkumarjigajinni@gmail.com
Cell No: 9431453730
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Cancer cell metabolism: special Reference to Lactate Pathway
Self learning material
1. SELF LEARNING MATERIAL
NAME-SHOBHA KUMARI
STUDENT ID-14162066
PROGRAMME -B. Ed 2014-15
BOARD-CBSE
CLASS-8
CHAPTER-CELL: STRUCTURE AND FUNCTION
2. CELL: STRUCTURE AND FUNCTION
To enable the learners to arouse prior knowledge of different sets of organs.
To enable the learners to classify cell: variation in number, shape and size.
To enable the learner toexplore structureof a generalizedcell, plant and animal
cell.
To enable to learners to devise cell division and growth.
As we already know about all living things carry out certain basic functions with
help of different sets of organs. Look at these pictures .
3. Cell are called structural unit of an organs. These may be compared to the bricks
of wall. As bricks are assembled to make a wall, similarly cells are assembled to
form an organism.
Let us find out more about cells.
CELLS: VARIATION IN NUMBER , SHAPE AND SIZE
The cell is the basic structural and functional unit of life; all organisms are
composed of cells. So we can say that “The smallest structuralunit of an organism
is called a cell. Cells of organisms show variation in terms of their number, shape
and size. Let us discuss each of these variations in detail.
Variation in Number
Bodies of organism consist of one or many cells. Organisms whose body consists
of a single cell are called unicellular organisms. Examples of unicellular organisms
are Amoeba, Paramoecium, Euglena and Bacteria .Thus in a unicellular organisms,
a single cell performs all vital activities like feeding, movement, respiration, and
reproduction. Organisms whosebody consist of many cells are called multicellular
organisms. Most plants and animals human beings are multicellular organisms
Variation in Shape
Cells exist in different shapes. They can be disc-shaped, polygonal, rectangular,
branched, or even irregular. The shape of a cell depends on the specific function it
performs. Here are a few examples that illustrate this.
Nerve cell Muscle cell
4. Nerve cell receives and transfers messages Musclecell helping to movement
Frombrain to body thereby helping to of body.
Control and coordinatethe working of
Different Parts of body.
Skin cell
Variation in Size
Most cells can be seen by microscope and cannot be seen by naked eye. Cell size
may vary from a micrometer to a few centimeters. The smallest cells are bacteria,
which generally range in size from 0.1 to 0.5 micrometer. The largest cell is the
egg of an ostrich, which is 170 millimeter in diameter. Human nerve cells are
believed to be the longest cells.
5. Test your knowledge:
Matchthe following:
A B
Unicellular organisms Human being
Amoeba
Multicellular organisms Banyan Tree
Paramoecium
Bacteria
Activity:
Aim: To observe a single cell(hen egg)
Material needed: A hen’s egg, a boiling pan, water
Method: Boiled the egg and remove the shell. Cut the boiled egg into two halves.
Observations: The boiled egg has a yellow part and a white part surrounding it.
The part is called albumin while the yellow part is called yolk. In an unboiled egg,
the albumin is a jelly-like transparent liquid. The yolk looks like a thicker yellow
jelly.
6. STRUCTURE OF A GENERALIZED CELL
As we know, cells may differ in shape and size ,all of them have the same basic
structure, referred to as the generalized cell. A cell has both living and non- living
parts. The living parts of the cell that have a definite shape, structureand function
are called organelles.
The main parts of a generalized cell are cell membrane, cytoplasm, and nucleus.
Cell membrane: Itis the outer covering of a cell. It is a porous membrane through
which selected substances can enter or leave the cell. The cell membrane is called
Plasma membrane.
Cytoplasm: It is a jelly- like fluid that fills up the part of the cell between the cell
membrane and nucleus. Several organelles are embedded in the cytoplasm.
Nucleus: It is considered to be brain of the cell.Nucleus is surrounded by a
membrane called the nuclear membrane and is filled with semi-solid substances
called nucleoplasm.Chromosomes carry genes, which transfer the characteristics
of a cell to the new cells that are formed during cell division.
Also present inside the nucleus is a round granule called nucleolus, which contains
a fibrous materials called chromatin fibres.
7. Here, this figure shows a generalized cell. It is important to note some of
organelles shown in this figure may be present only in plant cells and not in
animal cells and vice versa.
Structure of generalized cell
Let us learn about the cytoplasmic organelles shown in figure.
Golgi apparatus(or golgy body):It is made up of tubules(long tube-like
structures),vesicles(small vessels) and vacuoles and is responsible for the
secretion of chemical substances like enzymes,harmones, and proteins.
Vacuole: It is a fluid –filled space enclosed in a membrane. Vacuoles store excess
water, useful minerals, pigments, and many other substances.
Lysosomes: Lysosomes contain chemical substances called enzymes that are
capable of digestive cells and a variety of intra –and extra-cellular materials. In
8. terms of emergency, lysosomes burst and destroy the cell. Hence, they are also
called suicide bags of cell.
Endoplasmic reticulum: It is network of tubules and channels and is involved in
the synthesis, storage, and transport of cell products.
Ribosomes: These are small granular structures scattered in the cytoplasm that
act as sites of protein synthesis.
Centrosome: This structure is present only animal cells. The main function of
centrosomes is to initiate and regulate cell division.
Plastides: These are present in plant cells. Plastids contain certain pigments that
have a specific role to play in the functioning of the plant. Depending of the
pigment colour, plastids are of three kinds: chromoplasts ,chloroplasts, and
leucoplasts.
Choroplasts contain the green pigment chlorophyll, which helps plants in
making food .
Chromoplasts contain non green pigments that give colour to flower and
fruits.
Leucoplasts are colorless and store food in the form carbohydrates, fats,
and proteins.
Mitochondria(singular mitocondrian): These are tiny spherical or rod-shaped
bodies .They acts as sites of energy production and are, therefore, called the
powerhouse of the cell.
Test your knowledge:
Fill in the blanks with correct words.
1.The nucleus is filled with a semi-solid substances
called……………………(nucleoplasm/cytoplasm).
2.Chromosomes carry……………….(jeans/genes).
9. 3………………..(Ribosomes/Lysosomes are called suicide bags of the cell.
4…………………(Chloroplasts/Chromoplasts) contain the green pigment chlorophyll.
5………………….(Vacuoles/ Mitochondria )are called the powerhouse the cell.
Let us now examine the differences between plant and animal cells.
PLANT AND ANIMALS CELLS:
While plant and animals cells have the same basic structure, there are certain
differences between them.
Structure of Plant cell
10. Differences between a plant cell and an animal cell:
Plant cell Animal cell
1.Cell wall is present 1. Cell wall is absent.
2. Cytoplasm is not as dense as in an
animal cell.
2. Cytoplasm is dense.
3 .A large vacuole is present. 3. Vacuoles are generally absent, they
are small in size.
4 . Plastids are usually present. 4. Plastids are absent.
5. Centrosome is absent. 5. Centrosome is present.
11. Activity :
Aim: To prepare a temporary slide of an onion peel and the cells under a
microscope.
Material needed: Onion, blade, forceps, glass slides, coverslip, glycerine, iodine
solution, dropper, blotting paper, and microscope.
Method:
1. Cut the onion into four halves.
2. Separate the flashy scales with the help of a pair forceps and carefully peel
out a piece of the onion scale.
3. Place the peeled scale on a glass slide and add a drop of dilute iodine
solution to colour the onion peel.
4. Take another glass slide and put a drop of glycerin at its centre.Place the
coloured onion peel on the glycerine drop and carefully cover it with a
coverslip. Wipe any extra glycerine on the side of coverslip using a blotting
paper.
5. View the slide under microscope.
Observation: You should be able to see the large vacuoles and thick cell walls
peculiar to plant cells.
Prokaryotic and Eukaryotic Cells:
Cells that lack a well- defined nucleus surrounded by a nuclear membrane are
called prokaryotic cells. Organisms that have such cells are prokaryotes that
means pro, primitive, nucleus. Examples of prokaryotes are bacteria and blue -
green algae.
Cells that have well- defined nucleus are called eukaryotic cells. All organisms
apart from bacteria, blue green algae, and viruses are eukaryotes.
12. CELL DIVISION AND GROWTH:
The food that we eat leads to an increase in the size of cells. After reaching a
certain size, a cell divides into two by a process known as cell division. Increase in
the number of cells in the body as a resultof cell division is responsiblefor growth
in organisms .Cell division also replaces the dead or damaged cells with new ones
and is responsible for healing wounds.
Test your knowledge:
1. Define prokaryotic and eukaryotic cells?
2 . What is the function of cell division?
SUMMARY:
Cells of organisms show variation in terms of the number, shape, size of
cells.
Most cells can be viewed with the help of compound microscope.
Though cells may differ in size, all of them have the same basic structure,
referred to generalized cell structure or generalized cell.
Although plant and animal cells have the same basic structure, there are
certain differences between them.
Cell division is responsible for growth and healing of wounds in organisms.
EXERCISES:
A. Objective type questions:
I. Choose the correct option.
1.The lowest level of organization in a multicellular organism is the
(a.) cell (b) organ (c) tissue (d)organ system
13. 2. Skin cells cover a large area and are , therefore,
(a) Elongated (b) thin and long (c) flat (d) circular
3. The outer covering of a cell is the
(a) Nuclear membrane (b) enplasmic reticulum (c) cell membrane (d) chloroplast
4. Which of these is present only in animal cells?
(a) Cell wall (b) Centrosome (c) ribosomes (d)cytoplasm
5. Which of the following is responsible for growth?
(a) Healing wounds (b) cell division (c) cell maturity (d) differences in shape
II. WriteT for true statement and F for the false one. Correct the false statements.
1. A multicellular organism is made up of many cells.
2. Cells exist in different shapes.
3. Cell wall is present in the animal cell.
4. Chloroplasts give colour to flowers and fruits.
5. Bacteria and blue-green algae are examples of eukaryotes.
B. Very short answer questions:
I Write one word for the following.
1. Organisms whose body consists of a single cell. …………………………..
2. Organisms whose body consists of many cells. ……………………………..
3. Cells that have well-defined nucleus with nuclear membrane. …………………………
4. Cells that lack a well- defined nucleus. …………………………….
5 The powerhouses of the cell. ……………………………….
II. Write two examples for each of the following.
1. Kinds of plastids.
14. 2. Form in which food is stored in leucoplasts.
3. Prokaryotes
4. Eukaryotes
5. Unicellular organisms
C. Short answer questions
1. What is cell? What variations do the cells of organisms show?
2. Differentiate between unicellular and multicellular organisms?
3. With the help of examples, show how the shape of a cell depends on the
function it performs?
4 . What are cell organelles?
5. Name the different kinds of plastids?
6. Differentiate between eukaryotic and prokaryotic cells?
7. How cell division responsible for growth?
D. Long answer questions
1. With the help of examples, describe how cell vary in terms of shape, size,
and number?
2. With the help of a well-labeled diagram describe the different parts of a
generalized cell?.
3. What are the functions of different organelles in a cell?
4. Differentiate between plant cell and animal cell?
5. Describe stepwise how you would make a slide of a onion peel and observe
it under a microscope?