Key Area 1.1– Cell Stucture

Exercise 1

Research task on unicellular organisms

  • After doing some research, choose one example of a unicellular organism (single celled organism).
  • Make a labelled drawing of the organism.
  • Write a paragraph describing where it lives and how it obtains its food.
  • Write a list of references you used at the end.

Exercise 2

  1. Name THREE structural features that a typical plant cell and a typical animal cell have in common. (3)
  1. Name THREE structural features present in an Elodea leaf cell but absent from a cheek cell. (3)
  1. Give the function of each of the following structures: cell membrane, cell wall, nucleus. (3)

Total (9)

Exercise 3

1a)Identify FOUR structural features that a yeast cell has in common with an Elodea leaf cell. (4)

b)Name ONE structure absent from a yeast cell but present in Elodea. (1)

2A yeast cell can divide to form 2 cells in 30 minutes.

10 yeast cells are placed in a sugar solution.

a)How many yeast cells will be present after 2 hours?(1)

b)How long will it take for there to be over 1000

yeast cells?(1)

c)Name the process by which yeast cells reproduce.(1)

3Give the function of these cell structures.

a)Mitochondria

b)Ribosomes

c)Chromosomes(3)

4Bacterial cells have a main coil of DNA and other smaller rings of DNA.

a)What name is given to the smaller rings of DNA?(1)

b)What is their function in bacterial cells?(1)

c)What type of microscope is needed to see details of cell structures in small cells? (1)

Total (14)

Exercise 4

Research task on yeast

  • Research the uses of yeast in industry.
  • Describe the ways in which yeast is used in two different industrial processes. Write your information in two separate paragraphs.
  • Write a list of references you used at the end.

Exercise 5

Exam style questions

1.The diagram below represents a plant cell.

Which of the labelled parts of the cell are also found in an animal cell?

AM and N

BN and O

CM and P

DM, N, O and P

2.The diagram below represents a unicellular organism.

Which part indicates this is a plant cell?

3. Which line in the table below correctly matches the plant cell structure to its function?

Plant cell
structure / Function
A / Cytoplasm / Controls the chemical activities
B / Cell wall / Keeps the cells turgid
C / Vacuole / Prevents the cell from bursting in a hypotonic solution
D / Cell membrane / Controls which molecules enter or leave the cell

4.Which structural feature is common to both plant and animal cells?

ACell wall

BChloroplast

CNucleus

DLarge central vacuole

5.Which of the following prevents bursting of plant cells?

ANucleus

BCytoplasm

CCell wall

DCell membrane

6. Which plant cell structure is made of cellulose?

A Cell wall

B Cell membrane

C Chloroplast

D Nucleus

7.The diagram below shows onion cells as observed under a microscope at a magnification of 100 X.

300 micrometres

The diameter of the field of view is 300 micrometres. The average width of each cell in micrometres is

A0.38

B0.75

C37.5

D75.0

Question 8 and 9 refer to the diagrams of cells below.

8.Which cells are plant cells?

AP only

BP and Q

CP and R

DR only

9.The function of structure X is to

Acontrol all cell activities

Bkeep the cell turgid

Cproduce glucose using light energy

Drelease energy from glucose

10.Which line in the table below describes correctly the functions of the cell wall and chloroplasts in plant cells?

Function of
cell wall / Function of
chloroplast
A / prevents cell bursting / respiration
B / controls entry of
substances / respiration
C / prevents cell
bursting / photosynthesis
D / controls entry of
substances / photosynthesis

11.The diagram below shows a plant cell and an animal cell.

(a)Identify structure X.

(b)Give a function of the nucleus.

(2)

12.The diagrams below show sections of three different cell types.

They are not drawn to the same scale.

(a)(i)Copy and complete the table below to show the name and function of the parts labelled, X, Y and Z.

Part of cell / Name / Function
X
Y
Z

(ii)Cells A and B are plant cells and cell C is an animal cell.

Describe two features, shown in the diagrams, that support this statement.

(5)

13.Copy and complete the table.

Cell Structure / Function
Site of aerobic respiration
Ribosomes
Small rings of DNA in bacterial cells for reproduction

(3)

Total (20)

Exercise 6

Research task on bacteria

Choose one of the following research tasks:

A

  • Research the uses of bacteria in the dairy industries.
  • Describe how bacteria are used in the production of two different foods. Write your information in two separate paragraphs.
  • Write a list of references used at the end.

OR

B

  • Research diseases caused by bacteria
  • Describe two bacterial diseases, their symptoms and treatment. Write your information in two separate paragraphs.
  • Write a list of references used at the end.

Key Area 1.2 – TRANSPORT ACROSS MEMBRANES

Exercise 7

1.Name the two types of molecule present in the cell membrane.(2)

2.The cell membrane is sometimes described as a fluid mosaic structure.

a)Why is it described as fluid?

b)Why is it described as a mosaic?(2)

3.Cell membranes are selectively permeable.

a)What does this mean?

b)Name one substance which can pass through a cell membrane easily.

c)Name one substance which cannot pass through cell membranes.

d)Why is this substance unable to get through the membrane?

(4)

4.a)Name an artificial material used in experiments which is

selectively permeable.

b)Describe the test for starch.

c)What colour change would indicate a positive result for glucose with Benedicts solution? (3)

Total (11)

Exercise 8

Make a 3D cell membrane model

  • Your task is to make a 3D model of the cell membrane.
  • You can use any materials you can find at home, especially recycling materials.
  • Your model should show the proteins and the phospholipids with their head and tail ends.
  • The component parts should be labelled or there should be a key a identify them.
  • Examples of materials you could use include paper, cardboard, plastic bottle lids, plasticene, playdoh, straws, cotton buds, cocktail sticks, buttons, ribbons, fabric, lolly sticks, dry pasta, Lego, stickle bricks, k’nex.
  • THE POSSIBILITIES ARE ENDLESS SO HAVE FUN

Exercise 9

1.Name the two types of passive transport.(2)

2a)Name TWO essential substances that enter an animal cell

bydiffusion.(2)

b)Name a waste material that diffuses out of an animal cell.

(1)

c)What structure controls the passage of substances into and out of a cell? (1)

3a)Explain why diffusion is important to human beings.(2)

b)Predict what would happen to the rate of diffusion of oxygen into muscle cells if a person exercised vigorously. Explain your answer. (2)

Total (10)

Exercise 10

Research task on diffusion in the lungs

  • Do some research on diffusion in the lungs.
  • Make sure you find out about both of the main gases involved.
  • Write a paragraph about this diffusion.
  • Draw a diagram to show what happens, or print and stick in a diagram.
  • Make a list of the references you used at the end.

Exercise 11

1.Define the term diffusion.(1)

2.a)Describe the change in mass undergone by a cylinder of

fresh beetroot when it is immersed for 24 hours in

(i)water

(ii)concentrated sucrose solution(2)

b)What name is given to the special type of diffusion that causes these changes? (1)

c)What substance is gained or lost by the beetroot cells during this process? (1)

3.a)Define osmosis using these terms:

Lower water concentration, net movement, membrane,

water molecules, higher water concentration.(3)

b)Using the terms selectively permeable membrane andconcentration gradient of water, explain how the process of osmosis occurs. (2)

4.The diagram below shows four plant cells, P, Q, R and S.

If the plant cells remained in contact as shown, then water would pass by osmosis from BOTH:

A R to Q and Q to P

BQ to S and R to Q

CP to Q and R to S

DQ to P and Q to R(Choose ONE answer only)(1)

5.Three identical cylinders of fresh turnip were immersed in the liquids as shown below for 24 hours. Each was then removed and held between forefinger and thumb as shown in the second diagram.

a)Match numbers 1, 2, and 3 with letters A, B and C.(1)

b)Explain your choice in each case.(3)

Total (15)

Exercise 12

Research task on paramecium

  • Paramecium is a single celled animal that lives in fresh water.
  • Find out why it does not burst due to osmosis.
  • Make a labelled drawing of paramecium.
  • Describe how paramecium copes with the intake of water by osmosis.
  • Make a list of the references you need at the end.

Exercise 13

1a)Explain why red blood cells burst when placed in water yet

onion epidermal cells do not.(2)

b)Why do red blood cells shrink when placed in concentrated salt solution? (1)

2a)Describe the effect of very concentrated salt solution on onion epidermal cells. (1)

b)Explain why this happens.(1)

c)What name is given to cells in this state?(1)

d)How could these cells be restored to their turgid condition?

(1)

3Make a labelled drawing of a plasmolysed cell.(3)

Total (10)

Exercise 14

1a)Define the terms active transport.(1)

b)State two ways in which active transport is different from diffusion. (2)

c)Give an example of active transport in living cells.(1)

d)What molecules in the cell membrane are involved in active transport? (1)

2The diagram below shows the direction of movement of two different substances through the cell membrane of an animal cell.

a)Name processes X and Y.(1)

b)Which of these processes requires energy?(1)

c)Which of these processes does not occur in dead cells?

(1)

Total (8)

Exercise 15

Exam style questions

1.The following diagram shows the fluid-mosaic model of the structure of a cell membrane.

Which pair of structures numbered in the diagram are correctly identified in the following table?

PROTEIN / PHOSPHOLIPID
A / 1 / 7
B / 2 / 4
C / 3 / 7
D / 5 / 6

2.Diffusion is the movement of molecules of a substance from a region of:

Ahigh concentration to a region of low concentration of

the same substance

Blow concentration to a region of high concentration of the same substance.

Chigh concentration to a region of low concentration of a different substance.

Dlow concentration to a region of high concentration of a different substance.

3.Diffusion is important to the unicellular animal Amoeba because it is the means by which

Aoxygen, a useful substance, enters and CO2, a waste product, leaves.

BCO2, a useful substance, enters and oxygen, a waste product, leaves.

Coxygen, a waste product, enters and CO2, a useful substance, leaves.

DCO2, a waste product, enters and oxygen, a useful substance, leaves.

4.The movement of water through a selectively permeable membrane from an area of high water concentration to an area of low water concentration is called

A absorption

Bosmosis

Cplasmolysis

Dactive transport

5.A piece of potato weighs 20 g fresh and 5 g dry.

What is the percentage water content of the potato?

A5%

B15%

C25%

D75%

6.When animal cells are placed in water they

Aremain unchanged

Bburst

Cplasmolysed

Dbecome turgid

Question 7 and 8 refer to the accompanying diagram.

It shows the results of an experiment where turnip

cylinders, initially measuring 5 cm in length, were

immersed in three different liquids for 24 hours.

The test tubes were kept in a thermostatically

controlled water-bath during this time.

7.Which line in the following table correctly identifies liquids X, Y and Z?

Bathing liquid
X / Y / Z
A / 1 % sucrose / 0.3 % sucrose / Pure water
B / 1 % sucrose / Pure water / 0.3 % sucrose
C / 0.3 % sucrose / 1 % sucrose / Pure water
D / 0.3 % sucrose / Pure water / 1 % sucrose

8.The factor that was varied in this experiment was

Atemperature of bathing liquid

Blength of turnip cylinder

Cconcentration of sucrose solution

Ddiameter of turnip cylinder

9.The accompanying diagram shows four red onion cells immersed in four different solutions P, Q, R and S.

If the bathing solutions were arranged in order of increasing water concentration, the sequence would be:

AR, Q, S, P

BR, S, Q, P

CP, Q, S, R

DP, S, Q, R

10.Three plant cells, P, Q, R are shown below.

a)Water is moving from cell P to cell Q and from cell Q to cell R.

Which cell has the highest water concentration?(1)

b)If all three cells were placed in pure water for one hour, what term would be used to describe the resulting appearance of the cells? (1)

11.Three similar cylinders were cut from the same potato, dried and weighed. Each cylinder was placed in a different solution as shown in the diagram below.

0.5% Salt solution 1% salt solution water

After one hour, the cylinders were removed from the solutions, dried and reweighed.

(i)Copy and complete the table below by using the information in the diagrams.

(1)

Solution / Initial weight (g) / Final weight (g)
10 / 8
10 / 10
10 / 12

(ii)Which process has caused these changes in weight?(1)

(iii)The diagram below shows a cell from one on the potato cylinders.

What term would be used to describe the condition of this cell?

(1)

12.The diagram below shows the unicellular organism Paramecium which lives in fresh water.

a)Name the process by which oxygen moves from the water into the organism. (1)

b)Name a substance that moves from the organism into the water. (1)

d)Name the cell structure which controls the entry and exit of materials. (1)

Total (16)

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