Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
Cell structures
Cell wall
Description

(Cellulose cell wall)
(Cell wall is non living)


Plasma membrane

(Plasma membrane)


Cytoplasm


Nucleus
(contains most of the cellular
DNA)
(Control center of the cell)
Nuclear membrane (nuclear
envelope)


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Function
It is the outer tough  Protection
and rigid layer of
 Support
the plant cell.
 Gives shape to the plant
Cell wall is made
cell..
up of cellulose.
Animal cells have
no cell wall.
It is a double layer
 It isolates the contents of
or phospholipids
the cell from its external
embedded in a
environment.
variety of proteins.
 It regulates movement of
substances in and out of
It acts as a
selective barrier
the cell.
between the cell
 It allows interaction with
and its surrounding
other cells.
Jelly like substance Site of most chemical
reactions in the cell.
that contains
organelles.
The liquid portion
of the cytoplasm is
called cytosol.
It is a round double  It controls the activities of
membrane bounded
the cell.
organelle which
 It controls cell
contains most of
reproduction (it controls
the genetic material
cell division)
in the cell.
 It stores the cell’s genetic
material.
It is a double
membrane which
surrounds the
nucleus of
eukaryotic cells.
The nuclear
membrane contains
small holes called
nuclear pores.


It protects the nucleus.
It separates the materials
in the nucleus from rest of
the cell’s contents.
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
Nuclear pores
 Nuclear pores are
 It allows materials to pass
small holes on the
between the nucleus and
nuclear membrane.
cytoplasm.
Nucleolus

Chromatin

(Heredity material)

Ribosomes

(Rounded organelles found in
cytoplasm or attached on
Rough ER)


Rough Endoplasmic
Reticulum
(Rough ER)
Smooth Endoplasmic
Reticulum
(Smooth ER)
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



Small dark
structure in the
nucleus
Thin thread-like
structure, made up
of DNA and
proteins.
During cell
division,
chromatin
condenses into
chromosomes.
Ribosomes are
made up of RNA
and proteins.
Ribosomes are not
surrounded by a
membrane.
Ribosomes are
found in both
prokaryotic and
eukaryotic cells.
A network of
parallel
interconnected
membranous tubes.
Ribosomes attach
on the surface of
Rough ER.

A network of
parallel
interconnected
membranous tubes.
Has no ribosome
on its surface.

Synthesizes ribosomes
(site of ribosome
assembly)
Provides instructions for
the cell activities.

Site where proteins are
made (Synthesis proteins).

Transports proteins made
by the ribosomes.

Synthesis
lipids
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
 Golgi bodies are
 It separates or sorts
Golgi apparatus
membraneproteins and lipids
bounded
sacs
received from
(Golgi body or Golgi
found in most
endoplasmic reticulum
complex)
eukaryotic cells.
(ER).
 Golgi body was
 It modifies molecules.
discovered in 1898
 It packages materials into
by Camillo Golgi,
vesicles.
an Italian biologist
 Receives materials
(Sorting, modifying and
from ER.
packaging)
Lysosomes

(suicide bags in the cell)

Centrioles

(Found only in animal cells,
NOT in plant cells)
Mitochondria

(singular: mitochondrion)
Mitochondria contain DNA
and enzymes called ATPsynthase


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Lysosomes are
small spherical
bags surrounded by
a single membrane.
Lysosomes contain
digestive enzymes.

Centrioles are
hollow and
cylindrical
structures
consisting of nine
triplets of
microtubules.

Mitochondria are
rod-shaped with
double membrane
bounded organelles
found in the
cytoplasm of most
eukaryotic cells.
The inner folded
membrane of the
mitochondria is
called cristae and
contain a fluid
called matrix.
Contains enzymes
responsible for
synthesis of energy
for the cell.





Digest food particles in
the cell
Break down unwanted
substances
Digest poorly working or
malfunctioning organelles.
Play a role in cell division
by producing spindle
fibers.
Help cell division in
animal cells
Site of energy production
in the cell
(Power house of the cell)
Produces ATP in which
energy for cell activities is
stored.
(Site of many biochemical
reactions of aerobic
respiration)
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
 Chloroplasts are
 Chloroplast is the site of
Chloroplast
double membrane
photosynthesis.
bounded organelles
found only in plant Chlorophyll:
(contains its own DNA)
cells, not animal
 Traps sunlight energy
cells
 Makes leaves green in
 Chloroplast
color.
contains a
pigmented
molecule called
chlorophyll that
traps solar energy
for photosynthesis.
 Contains diskshaped structures
called thylakoids
Note:







Vacuole
(Plant cells have large
permanent vacuole, but animal
cells may have small vacuole)
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
The inner membrane of the chloroplast contains a semifluid material called stroma.
Stroma contains chloroplast DNA, ribosomes and
enzymes.
Stroma is the site of independent light reaction for
photosynthesis.
Thylakoids are site of light dependent reaction of
photosynthesis.
The stacks of thylakoids are called grana (singular:
granum)
Lamella connects and separates thylakoid stacks
forming grana.
Vacuole is a space
filled fluid cavity
surrounded by a
membrane called
tonoplast.
The fluid in the
vacuole is called
cell sap.



Storage of nutrients and
waste materials.
Stores water
Keeps the plant cell turgid
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
 Cytoskeleton is a
 Allows cell movement
Cytoskeleton
network protein
 Allows movement of
filaments found in
organelles within the
the cytoplasm of
cytoplasm.
most eukaryotic
 Allows movement of
cells.
chromosomes of
 The three types of
chromosomes during cell
cytoskeleton are:
division.
1. Microtubules
 Keeps the shape of the
(tubulin)
cells
2. Intermediate
 Supports the cell
filament
 It helps muscle
3. Microfilaments
contraction.
(actin microfilament)

Flagella
(singular: flagellum)

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Flagella are
microscopic hairlike structures
involved in the
cell locomotion
Bacteria and
sperm cells have
flagella.

Movement of the cell
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
Prokaryotic Cells
Eukaryotic Cells
(Pro= before, karyon=nucleus)
(Eu=true, karyon=nucleus)
Have no true nucleus
Have true nucleus
Do not contain membrane bounded
organelles
Contain membrane bounded organelles
Smaller
Larger
Ribosomes are small
Ribosomes are larger
Cell wall is present
Some contain cell wall e.g. plant cells, but
not animal cells
DNA is circular without proteins
DNA is linear with proteins
No mitochondria
Contain mitochondria
No cytoskeleton
Have cytoskeleton
Contain plasmid
Example, bacterial cell
Do not contain plasmid
Example, plant and animal cells
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
Part One: Multiple Choice Questions
1. The smallest structural and functional unit of an organism is called
A. Organelle
B. Organ
C. Cell
D. System
2. Which of the following structures serves as the cell’s boundary from its
environment?
A. Mitochondria
B. Cell membrane
C. Chloroplast
D. Channel proteins
3. Which organelle is responsible for the control of cell reproduction?
A. Nucleus
B. Ribosomes
C. Mitochondria
D. Golgi apparatus
4. The diagram below shows a cell.
The function of structure X is to
A. Control cell activities
B. Keep the cell turgid
C. Control entry and exist of material
D. Release energy from glucose
5. Which of the following is not surrounded by a membrane?
A. Nucleus
B. Ribosome
C. Chloroplast
D. Mitochondria
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
6. Which labeled structure is the chloroplast?
7. Which of the following organelles synthesizes proteins?
A. Mitochondria
B. Golgi body
C. Ribosome
D. Lysosomes
8. In what plant cell structure is water stored?
A. Chloroplast
B. Cell wall
C. Vacuole
D. Cytoplasm
9. A group of similar cells combined together to do the same function is called
A. Tissue
B. System
C. Cell
D. Organ
10. Which of the following organelles is the site where most chemical reactions take
place?
A. Nucleus
B. Ribosome
C. Cytoplasm
D. Nucleolus
11. Which cell structure receives materials from endoplasmic reticulum (ER) for
modifying and packaging?
A. Mitochondria
B. Cell membrane
C. Golgi body
D. Nucleus
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
12. The below diagram is about an animal cell.
What is the role of the labeled structure W?
A. Control center of the cell
B. Keeps the cell turgid
C. Controls cell activities
D. Controls in and out of the cell
13. Plant cell walls are made up of
A. Cellulose
B. Glycogen
C. Starch
D. Protein
14. What captures energy from sunlight to make food?
A. Cell membrane
C. Chloroplast
B. Cytoplasm
D. Cell wall
15. Structure commonly found in animal cells, but rarely in plant cells, is
A. Golgi apparatus
B. Nucleus
C. Centriole
D. Mitochondria
16. Which cell structure stores food, water and wastes?
A. Ribosome
B. Golgi body
C. Vacuole
D. Lysosome
17. The site where proteins are made is
A. Lysosomes
B. Vesicles
C. Mitochondria
D. Ribosome
18. Which cell organelle directs all activities of the cell?
A. Chloroplast
C. Nucleus
B. Nucleolus
D. Mitochondria
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
19. Which cell structures can be found in plant cells but not in animal cells?
A. Nucleus, cell wall
B. Chloroplast, mitochondria
C. Cell wall, cell membrane
D. Chloroplast, cell wall
20. The Primary function of the cell wall is to
A. Store DNA
B. Direct activities of the cell
C. Support and protect the cell
D. Help the cell move
21. Which cell organelle is responsible for breaking down or digesting substances?
A. Rough ER
B. Smooth ER
C. Nucleus
D. Lysosome
22. Rough endoplasmic reticulum (RER)
A. Transports lipids
B. Site of respiration
C. Transports proteins
D. Regulates movement
23. Animal cells __________
A. Have definite shape
C. Chloroplast present
B. Lack plasmodesmata
D. Are large size
24. The major component of cell wall in plant is
A. Glycogen
B. Cellulose
C. Water
D. Starch
25.
Smooth endoplasmic reticulum (SER)
A. Transports proteins
B. Site of respiration
C. Synthesis lipids
D. Synthesis proteins
26. Ribosome occur in
A. Only eukaryotic plant cells
B. Only eukaryotic plant cells
C. All eukaryotic cells
D. Both prokaryotic and eukaryotic cells
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
27. Which of the following types of molecules are the major structural components of
the cell membrane?
A. Phospholipids and cellulose
B. Nucleic acid and proteins
C. Phospholipids and proteins
D. Proteins and cellulose
28. In multi-cellular organism, the cell is unit of structure and also a unit of
A. Organization
B. Function
C. Strength
D. Foundation
29. Cytoplasm _____
A. is only found in animal cells
B. is important in initiating cell division
C. is the place where chromosomes are found
D. is the place where many chemical reaction occur
30. The structure that plays a role in cell division by producing spindle fibers is
A. Golgi apparatus
C. Lysosome
B. Centriole
D. Ribosome
31. A major difference between prokaryotic and eukaryotic cells is that
A. Prokaryotic cells have a flagellum
B. Eukaryotic cells have a nucleus
C. Prokaryotic cells have cytoplasm
D. Eukaryotic cells have ribosomes
32. Which of the following is true about the nucleus?
A. All cells have a nucleus
B. The nucleus contains all the cell’s DNA
C. The nucleus is considered the control center of the cell
D. All of the above
33. Which of the following is not true about the cell wall?
A. is made up of cellulose
B. is a living part of the cell
C. is found in plant cells
D. gives shape to the plant cells
34. Which of the following is the correct order of organization from simple to complex
A. Cell, organ, tissue
B. Tissue, cell, organ
C. Organ, cell, tissue
D. Cell, tissue, organ
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
35. Plant and animal cells are eukaryotic. This means they ______
A. Are able to multiply
B. Contain DNA
C. Produce energy
D. Have a nucleus
36. Which of the following structures is found in both plant and animal cells?
A. Cell wall
B. Chloroplast
C. Mitochondria
D. Large vacuole
37. What is the function of the cytoplasm
A. Stores water and mineral ions
B. Metabolic reactions occur in it
C. Control what enters and leaves the cell
D. Controls the actions of mitochondria
38. The cell theory states that
A. All organisms are made of one or more cells
B. All cells come from already existing cells
C. Cell is the smallest structural and functional unit of
organisms
D. All of the above
39. All the cells have the following, except
A. Cytoplasm
B. Genetic material
C. Plasma membrane
D. Nucleus
40. All of the following statements are about chloroplast and
mitochondria, except
A. Both use proton gradients for ATP production
B. Both capture light energy
C. Both contain DNA
D. Both are bounded by two unit membranes
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
Part Two: Structured Questions
1. The diagrams below show a plant cell and an animal cell.
(a) Name the parts labeled A, B, C, D, E and F
A. …………………..
D. …………………
B. ………………….
E. ………………….
C. ………………….
F. …………………..
(b) (i) Which of the two cells is a plant cell?
……………………………………………………………………………..
(ii) Give two reasons for your choice.
1. …………………………………………..
2. …………………………………………….
(c) Give one function of
(i)
Part B ……………………………………………………………
(ii)
Part C …………………………………………………………..
(iii)
Part E …………………………………………………………..
(iv)
Part A ……………………………………………………………
(d) Give the letters of two parts that are present in plant cells but not in animal
cells.
……………………………….. And ……………………………………………..
(e) Which part of the cell
i.
controls the passage of substances in and out of the cell.
……………………………………………………………..
ii.
is filled with cell sap.
……………………………………………………………
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
2. With reference to plant cells, complete the table below by writing the name of the
structure in column B that corresponds to the description in column A.
3. The diagram below shows a cell.
(a) Name the structures labeled A and B
A. ……………………………………..
B. ………………………………………
(b) The cell in the diagram is an animal cell.
How can you tell it is an animal cell and not a plant cell? Give two reasons.
1. ……………………………………….
2. ……………………………………..
(c) Oxygen will diffuse into the cell in the diagram. Why? Use information from
the diagram.
………………………………………………………………………………………….
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
4. Complete the table below which compares the structure of typical plant, animal
and prokaryotic cells.
5.
(a) State three differences between plant and animal cells
Plant cells
Animal cells
1
2
3
(b) What is the job (role) of each of the following parts of a cell?
i.
Nucleus …………………………………………………………….
ii.
Cellulose cell wall ………………………………………………….
iii.
Cytoplasm …………………………………………………………
iv.
Cell membrane ……………………………………………………
(c) i. What substance is contained in the chloroplast?
………………………………………………………………………………………….
ii. Why is this substance important to all living things?
………………………………………………………………………………………..
6. State the function of the following terms.
a. Mitochondria ……………………………………………………………………
b. Chloroplast ……………………………………………………………………..
c. Nucleolus ………………………………………………………………………
d. Golgi apparatus …………………………………………………………………
e. Flagellum ……………………………………………………………………….
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
7. The figure below is a diagram of cell as seen under light microscope.
(A) Name the structures that show that this is a plant cell
and not an animal cell.
A. …………………………….
B. …………………………….
C. ………………………………
(B) Name one chemical compound that is only found in the
structure labeled ‘A’ and state its functions.
………………………………………………………………
……………………………………………………………..
(C) What is the main chemical compound found in the
structure labeled ‘C’? State its functions.
……………………………………………………………..
………………………………………………………………
(D) Name the fluid found in part labeled ‘B’ and state its function
…………………………………………………………………………..
…………………………………………………………………………
(E) Name the structure that contains most of the cellular DNA
……………………………………………………………………………
8. The diagram shows a plant cell. Some structures in the diagram are also found in
animal cells.
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
9. In the table below, column 1 gives description of organelles found in eukaryotic
cells. Complete the table by writing the name of the organelle in column 2
10. Complete the table below by matching the parts of the cell in column A and its
correct function in column B by using letters.
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
ANSWER SHEET FOR PART ONE: MULTIPLE CHOICE QUESTIONS
1
2
3
4
5
6
7
8
9
10
C
B
A
A
B
A
C
C
C
C
11
12
13
14
15
16
17
18
19
20
C
D
A
C
C
C
D
C
D
C
21
22
23
24
25
26
27
28
29
30
D
C
A
B
C
D
C
B
D
B
31
32
33
34
35
36
37
38
39
40
B
C
B
D
D
C
B
D
D
B
ANSWERS FOR STRUCTURED QUESTIONS
Note: There may also be other possible answers for some questions.
1.
(a) .
A. Cell membrane
D. Cell wall
B. Cytoplasm
E. Chloroplast
C. Nucleus
F. Vacuole
(b) .
(i)
Cell Y is a plant cell
(ii)
Reasons: 1. Cell Y contains chloroplast 2. Cell Y contains cell wall
(c) .
(i)
Part B:site of most chemical reactions in the cell
(ii)
Part C:control center of the cell
(iii)
Part E:photosynthesis
(iv)
Part A:controls movement of substances in and out of the cell
(d) Chloroplast and cell wall
(e) .
(i)
A (cell membrane)
(ii)
F (vacuole)
18
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
2. .
3.
(a) A. Nucleus
B. Cell membrane
(b) Reasons: 1. It does not contain chloroplast 2. It does not contain cell wall
(c) Because there is higher oxygen concentration outside the cell
4.
5.
(a)
Plant cells
Animal cells
1
Have cell wall
No cell wall
2
Have chloroplast
No chloroplast
3
Have large permanent vacuole
have small vacuole
i.
ii.
iii.
iv.
Nucleus: control center of the cell (controls cell activities)
Cellulose cell wall: support and protection
Cytoplasm: site of chemical reactions in the cell
Cell membrane: controls movement of substances in and out of the cell
i.
ii.
Chlorophyll
Because it produces oxygen and glucose (food) which are important
for all living things.
(b)
(c)
191
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Form 4 Biology
Chapter 7 – Cell Biology – Cell Structure and Function
Summary Note with Exam Practice and Answer Key
6.
a. Mitochondria: power house of the cell (produces energy)
b. Chloroplast: photosynthesis
c. Nucleolus: synthesis ribosomes
d. Golgi apparatus: it modifies molecules, or it packages materials into vesicles
e. Flagellum: movement of the cell
7.
(A)
A. Vacuole
B. Chloroplast
C. Cell wall
(B) Chlorophyll. It traps light energy. It makes leaves green in color
(C) Cellulose. It supports the plant cell
(D) Cell sap. It stores nutrients and waste materials. Or it stores water
(E) Nucleus
8.
a)
9.
10. Matching column A and column B
a) -------- 4
b) -------- 1
c) -------- 3
d) -------- 5
e) --------- 2
END
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