The document discusses the structure and function of cells. It defines the key parts of animal, plant, and bacterial cells including the cell membrane, nucleus, cytoplasm, chloroplasts, and cell wall. It compares the relative sizes of different cell types and the structures present in eukaryotic versus prokaryotic cells. The document also explores specialized cell types and how cells, tissues, organs, and organ systems work together in living organisms.

1. Chap: 2 Cells
By:Zainab Kulsoom

2. • To identify and label the parts of a typical animal cell, plant cell.
• To compare the relative sizes of different types of cells.
• To compare the structure and function of eukaryotic and prokaryotic cells.
.
Learning Objective
Success Criteria

3. Starter
The image below shows some onion cells under a light microscope.
Can you identify any of the parts of the cell?
Photo courtesy of (@wikimedia.org) - granted under creative commons licence – attribution

4. Starter
cell membrane
cell wall
cytoplasm
nucleus
Photo courtesy of (@wikimedia.org) - granted under creative commons licence – attribution

5. A Cell
A cell is the unit of
life.
It was first
discovered by
Robert Hooke in
1665.
Cells perform
different jobs in
organism’s body.
The organelles
present inside the
cell are contributing
in the efficacy of
the cell function.

6. An Animal Cell
A typical eukaryotic cell.
Enclosed by a plasma membrane.
Membrane bounded nucleus and
organelles are present.
The size of animal cell ranges between
1 and 100 micrometer, thus only visible
under a microscope.
Animal cell is capable of developing
great diversity of cell types, tissues and
organs.
Specialized cells are performing
specialized functions in animal’s body.

7. Characteristics Of Cells
Plasma
Membrane
• A surrounding membrane.
• Protects the cell.
Protoplasm
& Organelles
• Cell contents in thick fluid
• Structures for cell function.
Nucleus
• Contains hereditary information.
• Controls all the activities of the cell.

8. Cell Membrane/ plasma membrane/cell surface
membrane
• Separates the inside of the cell from the
outside environment.
• Partially permeable to control substances
entering or leaving the cell.
• Selective permeability
• Allowing some substances to cross more easily
than others.
• Block passage of some substances altogether.
• Consists of A Lipid Bilayer ( Phospholipid
Bilayer).

9. Cytoplasm & its Function.
• It’s the living portion of the cell.
• All the organelles are embedded in
cytoplasm, thus it’s responsible to
carry out all the life processes.
• Composition Of Cytoplasm.
• It’s mainly composed of water, salts
and proteins.
• It lacks any color pigment so gives
transparent appearance.

10. Ribosomes And Their Function.
Ribosomes are the minute rounded
bodies present inside the cell.
There are two types of Ribosomes
,i.e;
Free floating
Attached to Endoplasmic reticulum.
Composition of ribosomes:
Made up of RNA and proteins.
Also called as macromolecular
machines which synthesize proteins.

11. Nucleus
• The control center of the cell.
• It contains the hereditary material
called DNA.
Definition
• Nucleus is a membrane bound
organelle that controls all the activities
in cell.
• It’s present in the center of the cell.
Position Of
Nucleus.
• The DNA is enclosed in a nuclear
envelop that contains small pores
which help to regulate the nuclear
transport of molecules across the
membrane.
Function Of Nuclear
Envelope

12. Plant Cell
Sub-cellular Structures
nucleus
contains genetic
information and controls
the activities of the cell
mitochondria
site of aerobic
respiration, which
releases energy for the
cell
cell membrane
controls the movement
of substances into and
out of the cell
cytoplasm
jelly-like substance
where chemical
reactions occur
ribosome
carries out protein
synthesis using the
genetic code from DNA
cell wall
strengthens the cell and
provides support
permanent vacuole
contains cell sap to keep
the cell rigid
chloroplast
contains chlorophyll, which
absorbs light energy for
photosynthesis

13. Sub-Cellular Structures
Bacterial Cell
cell membrane
controls the movement of substances into
and out of the cell
cytoplasm
jelly-like substance where chemical
reactions occur
ribosome
carries out protein
synthesis using the
genetic code from DNA
flagellum
tail-like structure that allows the cell to
move
cell wall
strengthens the cell and provides
support
plasmid
small ring of DNA that codes for specific
functions
DNA loop
carries genetic information

14. Relative Size of Cells
Bacterial cell is typically 0.5
- 5μm in length,
approximately 10 times
smaller than plant cell.
Animal cells are
typically between
10 - 30μm in length.
Plant cells are larger than
animal cells and range from
10 - 100μm in length.
1 millimetre (mm) = 0.001m
1 micrometre (μm) = 0.000001m
1 nanometre (nm) = 0.000000001m
smallest largest

15. Comparing Cells
Part of the cell Animal Cell Plant Cell Bacterial Cell
Plasma Membrane ✔ ✔ ✔
Cell Wall ❌ ✔ ✔
Cytoplasm ✔ ✔ ✔
Plasmid ❌
❌
✔
Nucleus ✔ ✔ ❌
Ribosomes ✔ ✔ ✔
Flagellum ❌ ❌ ✔
Chloroplast ❌ ✔ ❌

16. Plenary
You have 60 seconds to summarise the lesson and what you have learned today. You
could do this as a mind map, diagram or doodle, a short sentence or even a list of
keywords.
60 Second Challenge
start finish

17. To understand the term cell, tissue, organ and organ system and
organisms as illustrated by examples.
To understand that cells can become specialized and that their
structures are related to their specific functions, as illustrated by
examples.
.
Learning Objective 1
Learning Objective 2
Specialized Cells, Tissues, Organ
and Organ System

18. Definition
A cell that becomes
specialized to perform a
specific function is called as
specialized cell.
Such kind of cells are present
in both plants and animals.

19. Root Hair Cell.
It has nucleus and a vacuole.
It’s long and narrow.
It increases the surface area to
volume ratio of the cell.
Helps in efficient absorption of
water and mineral salts from the
soil.

20. Red Blood Cell
It’s circular and biconcave in shape.
Contains a red color pigment hemoglobin
that absorbs oxygen from the lungs and
delivers to all parts of the body.
The shape of RBC increases the surface
area for the quick diffusion of oxygen.

21. Xylem Vessels
Water conducting tissues.
Cross walls and protoplasm are absent in xylem vessels.
Also called as dead cells.
Lumen (space) enables the continuous flow of water.
Lignin is a hard substance, present in walls of xylem.
It strengthens the walls and prevents collapse of
vessels.

22. Tissues
Cells of the same type group together to form
tissues.
Such tissues have different functions to
perform.
Examples;
Epithelial tissue: A sheet of muscle which
cover both the internal and external organs.

23. Tissues
Plant Epidermis is a
covering tissue.
It’s thin and have
nucleus.

24. Tissues
Bone tissue makes
bones.
Nervous tissue
makes the
nervous system.

26. Organs
Different tissues are united to make organs.
These tissues enable the organ to perform its
function.
Examples:
Stomach, Liver, Heart, Brain, Bones and in plants;
stem, root, leaf and flower are the organs which
are made up of different types of tissues.

27. Organs System
Several organs working together for a
special purpose make up an Organ
System.
Examples:
Digestive System, Circulatory system,
Respiratory System, Nervous System,
Reproductive System, Excretory system.

28. Plenary
You have 60 seconds to summarise the lesson and what you have learned today. You
could do this as a mind map, diagram or doodle, a short sentence or even a list of
keywords.
60 Second Challenge
start finish