National 5 BiologyWilliamwood High

School

Cell Biology Homework Booklet

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Homework 1- Cell Structure

Q2

2

Q2

3

4

Q4

Q3

Q53 and 4

Q6

7. Name four structural features that a typical animal cell and a typical plant cell share.

(1) 8. Name three structural differences between a typical animal cell and a typical plant cell.

(1) 9. Give the function of each of the following structures: (a) Cell membrane (b) Cell wall (c) Nucleus (d) Chloroplast (e) Vacuole (f) Cytoplasm (g) Mitochondrion (h) Ribosomes

(3)

Total-20

Homework 2- Transport across cell membranes

5

2

1

Which line in the table below shows what happens to cells when placed in a

concentrated salt solution?

6

3

7

4

8

Using the results given, state the salt concentration which has the same water concentration as the potato tissue. Explain your answer.

9

5

6

Q7. Copy and complete the table below. Decide if each of the following statements is TRUE or FALSE and tick the appropriate box. If the statement is FALSE, write the correct word in the correction box to replace the word underlined in the statement.

(4)

Statement True False CorrectionMolecules of carbon dioxide move out of a respiring cell by diffusion.The carrier molecules that pump ions across a membrane are made of phospholipid.Red blood cells shrink when placed in distilled water.During active transport, energy is needed to move molecules along a concentration gradient from low to high concentration.

Total- 20

Homework 3- DNA and the production of proteins

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Q3. Calculate the percentage of guanine molecules which would be present in a DNA molecule of 6000 bases if 1200 are adenine. (Show your calculations) (2)

Q4. Where is mRNA made in a cell? (1)

Q5. What is the function of mRNA? (1)Q6. Where are proteins made in the cell? (1)

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7

1 2

Q8. Name the 4 bases that are found on DNA. (1)

12

Q9. What composes the backbone of the DNA double helix? (1)

13

10

Total- 20

Homework 4- Proteins

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3

15

4

Q5. Enzymes are made from protein, name another molecule that is made from protein.

(1)

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6

17

7

8

1

Total-20

18

9

1

Homework 5- Genetic Engineering

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2

1

3

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4

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5

6

Q7. The following steps are involved in the process of genetic engineering.

1. Insertion of a plasmid into a bacterial host cell.2. Use of an enzyme to cut out a piece of chromosome containing a desired gene.3. Insertion of the desired gene into the bacterial plasmid.4. Use of an enzyme to open a bacterial plasmid.Which is the correct sequence of these steps?

A. 4, 1, 2, 3 B. 2, 4, 3, 1

C. 4, 3, 1, 2 D. 2, 3, 4, 1 (1)

8. Genetic engineering can be used to transfer human genes to bacteria artificially.

Complete the boxes below to describe each of the steps carried out to transfer a human gene into a bacterial cell.

(3)

Step 1

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Chromosome extracted from human cell and

required gene located

Bacterial cell carrying plasmid identified

Step 2

Step 3

Step 4

Q9. What is used to cut the desired gene from the chromosome? (1)

Total-20

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Grow large numbers of the bacteria now containing required human gene.

Step 5

Homework 6- Respiration

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4. Which of the following stages in respiration would result in the production of a large number of ATP molecules?

A Glucose to pyruvate

B Pyruvate to lactic acid

C Pyruvate to carbon dioxide and water

D Glucose to carbon dioxide and water

2

5

Q6. a) State the end products of:

1. Aerobic respiration2. Fermentation in plants (2)

b) State the location of:

1. Aerobic respiration2. Fermentation (2)

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1

c) Name a cellular process that ATP is required for. (1)

Q7.

b) How many times more energy is released from Type of cell respiration A compared to C? 1

Describe a suitable control for this investigation

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8. The diagram shows apparatus used in an investigation of aerobic respiration in snails.

Lactate produced (g)

a) Describe a suitable control for this experiment. 1b) How could this experiment be made more reliable? 1

Total-20

Homework 7- Experimental design

1. An investigation was carried out to find the effect of salt solutions of different concentrations on the mass of potato tissue. Five test tubes were set up as shown below, each containing a different concentration of salt solution.

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Each potato cylinder was weighed, placed in the solution and left for an hour. Each cylinder was then reweighed and the percentage (%) change in mass was calculated. The table below shows the results of the investigation.

a) i) Add the appropriate label to each axis. 1 ii) Construct a line graph using the results given in the table. 1

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b) Time was kept constant in this investigation. Name two other variables which must be kept constant. 1._______________________________2.__________________________

2 c) Using the results given, state the salt concentration which is equal to the salt solution in the potato tissue. Explain your answer. Isotonic concentration _________________g/100cm3 Explanation ___________________________________________________________

2 d) Predict the salt concentration that would produce a 10% decrease in mass. _________________g/100cm3

12. An investigation was carried out to look at the effect of adding three different solutions to three pieces of muscle tissue. The results of the investigation are given in the table below.

a) Complete the table by calculating the percentage difference in length for muscle tissue 3.

1 b) What conclusion can be drawn from the results? ___________________________________________________________

1 c) Why is it necessary to use percentage difference in this experiment? ___________________________________________________________

1 d) Explain why three different syringes should be used in this investigation. ___________________________________________________________

1

3. Four groups of students investigated the catalase concentration of different tissues. Each group set up a test-tube containing 5 cm3 of hydrogen peroxide and a cube of potato. The oxygen was collected over a 3 minute period and the volume was measured as shown in the diagram below.

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This procedure was repeated by each group using cubes of liver, apple and carrot. The results from the four groups are given in the table below.

a) Complete the table to show the average volume of oxygen collected for potato tissue. Space for calculation

1

b) The volume of hydrogen peroxide and time taken to collect the oxygen were kept constant in this investigation. State two other variables that must be kept constant. 1.__________________________________________________________ 2.__________________________________________________________

2 c) What was done in this investigation to make the results reliable? ___________________________________________________________

1 d) What conclusion can be drawn from these results? ___________________________________________________________ ___________________________________________________________

1 4. The apparatus shown below was used to study the effect of different temperatures on the activity of the enzyme catalase.

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The catalase was added and reacted with the hydrogen peroxide to release oxygen. The increase in oxygen compared to the starting value was recorded as a percentage. This was carried out at five different temperatures and the results are shown below.

a) Use the results to draw a line graph.

2

b) Why was it important that the catalase and the hydrogen peroxide were both at the required temperature before the catalase was added?

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___________________________________________________________ ___________________________________________________________

1

c) Calculate the simple whole number ratio of percentage increase in oxygen at 34 °C, 40 °C and 50 °C.

1

Total- 20

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