Cell Biology and Organisation

Question 1

Give three differences between prokaryotic cells and eukaryotic cells (3 marks)

Answer 1

-prokaryotic cell is smaller (1 mark)
-prokaryotic cell has no nucleus (1 mark)
Prokaryotic cell has a single loop of DNA

Question 2

What happens during each stage (3 stages) of the cell cycle (4 marks)

Answer 2

Stage 1- DNA duplicates (1 mark) sub-cellular structures replicate (1 mark)
Stage 2- one set of chromosomes is pulled to each end of the cell (1 mark)
Stage 3- the cytoplasm and cell membrane divides to for two daughter cells (1 mark)

Question 3

What is the main type of tissue in the heart wall (1 mark)

Answer 3

Cardiac muscle

Question 4

Explain how a stent helps to prevent a heart attack (3 marks)

Answer 4

The atrium contracts (1 mark) blood pushes ball down (1 mark) this opens the valve which allows blood into the ventricle (1 mark)

Question 5

Culturing microorganisms required practical steps:

Answer 5

Step 1- sterilise all Petri dishes, bacteria nutrients broth and agar
Step 2- sterilise the inoculating loop by passing it through a Bunsen burner flame
Step 3- attach the lid to the Petri dish use adhesive tape to keep it in place and avoid unwanted microorganisms from entering
Step 4- turn agar plate upside down into an incubator. This stops any moisture from dripping down onto the bacteria and disrupting the colonies.
Step 5- set the temperature in the incubator to 25°C. This reduces the chances that harmful bacteria will grow.

Question 6

Define osmosis

Answer 6

Osmosis is the movement of water particles across a partially permeable membrane from an area of high concentration to an area of low concentration

Question 7

What is the name of the vein on the right side of the heart and what is its role?

Answer 7

Vena cava
Carries deoxygenated blood from the body back to the heart

Question 8

What is the name of the artery on the right side of the heart and what is its role?

Answer 8

Pulmonary artery
Carries deoxygenated blood to the lungs

Question 9

What is the name of the vein on the left side of the heart and what is its role?

Answer 9

Pulmonary vein
Transports oxygenated blood from the lungs back to the heart

Question 10

What is the name of the artery on the left side of the heart and what is its role?

Answer 10

Aorta
Transports oxygenated blood from the heart to the body

Question 11

What is the role of arteries?

Answer 11

They carry blood away from the heart

Question 12

What is the role of capillaries?

Answer 12

They are involved in the exchange of materials at the tissue

Question 13

What is the role of veins?

Answer 13

They carry blood to the heart

Question 14

What are the different adaptations of arteries?

Answer 14

Strong elastic walls so that the blood can be pumped out at high pressure.
The walls are thick

Question 15

What are the different adaptations of the capillaries?

Answer 15

They are really small so that they can carry the blood really close to every individual cell.
They have permeable walls so substances can diffuse in and out.
The walls are only one cell thick, which increases the rate of diffusion.

Question 16

What are the different adaptations of veins?

Answer 16

They are wider so that the blood can flow despite the low pressure
They have valves to keep the blood flowing in the right direction

Question 17

What are communicable diseases?

Answer 17

There are diseases that can spread from person to person or between animals and people they can be caused by things like bacteria, viruses, parasites, and fungi

Question 18

What are non-communicable diseases?

Answer 18

They are diseases that cannot spread between people or between animals and people they last for a long time and get worse slowly, for example, asthma, cancer, and coronary heart disease.