NATIONAL 4 AND NATIONAL 5 BIOLOGY HOMEWORK
CELL BIOLOGY
UNIT 1: CELL STRUCTURE
HOMEWORK 1
1. What are the units from which all living things are made?
2. What is the advantage of staining cells before examining?
3. a) Draw, in pencil, a diagram of a plant cell and label the following :
cell wall,
cell membrane,
cytoplasm,
nucleus,
vacuole,
chloroplast,
mitochondrion, ribosomes.
b) Which of these structures are found in both plant and animal cells?
c) Which structures are only found in plant cells?
4. State the functions of the;
a) nucleus, b) cytoplasm, c) mitochondria, d) ribosomes
HOMEWORK 2
Create a 3D PLANT cell model.
You must include the following structures and ensure they are labelled. Use a key if you
wish.
 cell wall, cell membrane, cytoplasm, nucleus, vacuole, chloroplast, mitochondria
and ribosomes
HOMEWORK 3
1. Name the two components of the cell membrane.
2. Describe the permeability of the cell membrane.
3. Draw, in pencil, a labeled diagram of the fluid mosaic model.
HOMEWORK 4
1. Write a definition of diffusion.
2. Using an example, explain why diffusion is important to humans.
3. a) Name one substance which leaves an animal cell by diffusion.
b) Name two substances which enter an animal cell by diffusion.
HOMEWORK 5
1. What type of molecules pass into and out of cells by osmosis?
2. Write a definition of osmosis.
3. a) Describe what happens to a plant cell when placed in pure water
and explain why this happens.
b) Describe what happens to a plant cell when placed in a strong salt
solution and explain why this happens.
4. a) Describe what happens to an animal cell when placed in pure water
and explain why this happens.
b) Describe what happens to an animal cell when placed in a strong
salt solution and explain why this happens.
5. What names describe plant cells which have been placed in;
a) water
b) a strong salt solution
HOMEWORK 6
1. Write a definition of Active Transport.
2. Name two examples of molecules which move by Active Transport
UNIT 2: CELL DIVISION & INHERITANCE
HOMEWORK 1
1. Why is cell division important to multicellular organisms?
2. What name is given to the division of the nucleus?
3. Compare the diploid daughter cells with their parent cell:
a) the number of chromosomes
b) the information (instructions) they contain.
4. What must happen to a chromosome before a cell can divide?
5. Draw a pencil diagram of a chromosome and label:
the chromatids; the centromere
HOMEWORK 2
1. What are chromosomes and where are they found in a cell?
2. How many chromosomes are found in a human body cell?
3. Draw the table below and indicate with a  whether each of the cells would have a
double or single set of chromosomes.
Cell Type
Single set of chromosomes
Double (Diploid) set of
chromosomes
Skin
Muscle
Egg
Sperm
4. Copy the passage below filling in the missing words to make the sentences correct.
Genes are located on chromosomes in the _________. Genes are made of DNA which
carries the instructions to make _________. Each individual’s DNA is ___________.
HOMEWORK 3
1. The table below refers to the chromosome complement (total number of chromosomes
in a cell) of seven crop plants.
Species of crop plant
Broad bean
Rye
Garlic
Radish
Maize
Wheat
Oat
Number of chromosomes in chromosome
complement
12
14
16
18
20
28
42
a) Draw a bar graph of this information.
b) State the number of chromosomes present in the chromosome complement of a garlic
plant.
c) Express as a simple whole number ratio the chromosome complement of oat to rye.
d) In terms of chromosome number, the chromosome complement of oat exceeds that of
one of the others by 3.5 times. Identify the plant.
UNIT 3: DNA TO PROTEINS
HOMEWORK 1
1. What are the three components of a nucleotide?
2. What is the name of the base that pairs with adenine?
3. What is the name of the base that pairs with guanine?
4. If you know that the sequence of bases on one DNA strand was AGCTCAG. What
would the sequence of bases be on the opposite strand?
5. If a DNA double helix contained 100 base pairs and there were 40 cytosines, how
many adenines would there be?
UNIT 4: ENZYMES IN ACTION
HOMEWORK 1
1. What do catalysts do?
2. a) What are enzymes?
b) Are enzymes changed by the reactions they are involved with?
3. Why do cells need enzymes?
HOMEWORK 2
1. What is a “substrate”?.
2. Describe a breakdown reaction controlled by an enzyme by naming:
a) the substrate
b) the products
c) the enzyme
3. Describe a synthesis reaction controlled by an enzyme by naming:
a) the substrate
b) the products
c) the enzyme
HOMEWORK 3
1. What type of chemical are enzymes made of?
2. Describe the effect on the activity of the enzyme catalase of changing the
temperature from 15C to
a) 5C
b) 25C
c) 55C
3. Use the words “active” and “inactive” to describe the effects of different
pH on the activity of the enzyme pepsin.
a) pH 3
b) pH 6
c) pH 9
HOMEWORK 4
1. What does “specific” mean when describing enzymes?
2. What does “optimum” mean when describing enzyme activity?.
3. What are the optimum pH’s for:
a) pepsin
b) catalase
UNIT 5: RESPIRATION
HOMEWORK 1
1. What type of energy does food contain?
2. Which types of food contain the most energy per gram?
3. Describe three different uses for energy in cells
4. a) What is respiration?
b) What gas is used by cells during aerobic respiration?
c) Write a word equation for aerobic respiration.
5. a) What gas is given produced as a waste product of respiration?
b) What is this gas produced from?
6. What type of energy is produced by respiring cells?
HOMEWORK 2
1. Why is production of heat energy by respiring cells in the human body important?
2. Give the full name of the chemical represented by the letters ATP and draw a
simple labeled diagram of an ATP molecule
3. Glycolysis is the first stage of respiration. Where does this occur and what are the
products of this stage?
4. State the products of the second stage of respiration if oxygen is present
HOMEWORK 3
1. Rewrite the following statements, referring to anaerobic respiration in human
muscle, in the correct order.
Lactic acid builds up
Oxygen supply becomes limited
Muscles suffer fatigue
Lactic acid is produced
2. Explain why anaerobic respiration in animal cells is reversible
3. Name the products of anaerobic respiration in plants and yeast. Use this to explain
why this process is not reversible
HOMEWORK 4
1. A live worm is placed in a sealed boiling tube and left for 4 hours.
What changes will take place in the composition of the air during this time?
2. a) What is meant by metabolism?
b) What two types of reaction are involved in metabolism?
3. Why is respiration important to the metabolism of cells?
UNIT 6: PHOTOSYNTHESIS
HOMEWORK 1
1. a) What are the raw materials required for photosynthesis?
b) What are the essential requirements of photosynthesis?
2. What is the structure and function of cellulose?
3. Why must a control be used in an experiment?
HOMEWORK 2
1. In photolysis write down the energy change that is taking place
2. a) Draw out the photolysis diagram
b) Underline the 2 products that go on to the next stage and circle the one that leaves
the cells.
HOMEWORK 3
1. Draw the diagram showing all the stages of carbon fixation.
2. Name the substance that is taken from the air.
3. How are these reactions controlled?
4. What is the end product?
HOMEWORK 4
Use the graph below to answer the flowing questions
1. At point A what is the limiting factor?
2. Why is this no longer the limiting factor at point B?
3 Give 2 other factors that could be limiting at point B
B
A
Carbon Dioxide concentration
HOMEWORK 5
1. Look at your jotter and write a key words list with definitions in your homework jotter
there should be at least 5 words.
2. Construct a summary of the photosynthesis topic. It can be a mind map or lists or notes
but must contain all the information from this topic.
UNIT 7: BIOTECHNOLOGY & ‘CONTROVERSIAL BIOLOGY’
HOMEWORK 1
1. Yeast is a single-celled organism. What is the proper term for ‘single
celled’?
2. a) What is respiration?
b) Yeast respiration occurs in the absence of which gas?
3. What is bicarbonate indicator used to test for?
HOMEWORK 2
1. Name three commercial products which require the activity of yeast.
2. Think about the use of yeast in fermenting grape juice to alcohol. A pupil said that
yeast could be described as ‘its own worst enemy’. Why do you think this is?
3. Summarise the use of Benedict’s solution in testing for a simple sugar. Be sure to
include the colour change expected in the presence of a simple sugar and the preparation
involved.
HOMEWORK 3
1. Name two dairy products produced with the activity of bacteria on milk.
2. Name the acid formed by the fermentation of lactose sugar.
3. With the use of a labelled diagram, describe the process of biological filtration.
4. What is the purpose of agar jelly in a microbiology lab?
5. Safety is important in the microbiology lab. Give two examples of important
precautions which are taken to avoid escape of potentially hazardous microbes.
HOMEWORK 4
1. Draw a flow chart to show the process of genetic engineering.
Remember that
labels are essential!
2. Mrs Ruby Tackle washes the local rugby team kit. Explain why it would be beneficial
for her to use biological detergent.
USER NOTES:
Should you require any assistance with homework activities, your
teacher should be approached immediately.