Cell Structure and Organisation

Question 1

Function of the cell membrane

Answer 1

The cell membrane is partially permeable to allow only small and soluble substances to pass through

Question 2

Function of the cell wall

Answer 2

The cell wall protects the cell from injury and gives it a fixed shape

Question 3

Function of the cytoplasm

Answer 3

The cytoplasm is the site of cellular activities

Question 4

Function of the nucleus

Answer 4

The nucleus controls cellular activities and is essential for cellular division

Question 5

Function of the rough endoplasmic reticulum

Answer 5

The rough endoplasmic reticulum transports proteins made by the ribosomes to the Golgi body

Question 6

Function of ribosomes

Answer 6

Ribosomes are responsible for protein synthesis

Question 7

Function of the smooth endoplasmic reticulum

Answer 7

The smooth endoplasmic reticulum
1. synthesises substances such as fats and steroids
2. Is involved in detoxification

Question 8

Function of the Golgi body

Answer 8

The Golgi body
1. chemically modifies substances from the rough endoplasmic reticulum
2. Stores and packages the substances in vesicles for secretion out of the cell

Question 9

Process of secretion out of the cell

Answer 9

1. Vesicles containing substances made by the rough endoplasmic reticulum pinch off from the RER
2. Vesicles fuse with the Golgi body releasing substances made by the rough endoplasmic reticulum to be modified
3. Secretory vesicles containing modified substances pinch off from the Golgi body and move towards the cell membrane
4. Secretory vesicles fuse with the cell membrane and their contents exit the cell

Question 10

Function of the mitochondria

Answer 10

The mitochondria is the site of aerobic respiration (release energy for cellular activities such as protein synthesis and cell growth)

Question 11

Function of chloroplasts

Answer 11

Chloroplasts contain the green pigment, chlorophyll which captures sunlight for photosynthesis to occur

Question 12

Function of vacuoles

Answer 12

Vacuoles store substances within the cell

Question 13

Difference between vacuoles in an animal cell and a plant cell

Answer 13

Plant cells have a large central vacuole while animal cells have numerous small vacuoles

Question 14

What is Differentiation?

Answer 14

It is the process by which a cell becomes specialized for a specific function

Question 15

What are the adaptations of red blood cells

Answer 15

1. They contain haemoglobin which binds to oxygen and transports it around the body
2. They have a circular biconcave shape which increase SATV ratio to increase the rate of oxygen uptake
3. They do not contain a nucleus which allow more haemoglobin to be on the cell for more oxygen to be transported
4. They are flexible which allow them to easily squeeze through capillaries

Question 16

What are the adaptations of muscle cells

Answer 16

1. They contain many mitochondria to provide more energy for the contraction of muscle cell
2. They have contractile protein fibres which allow the contraction and relaxation of muscle to bring about movement
3. They have many nuclei to allow for cell division

Question 17

What are the adaptations of root hair cells

Answer 17

1. They have a long narrow extension which increases SATV ratio to increase the rate of absorption of water and mineral salts
2. They maintain a lower water potential in vacuole to allow water to enter the root hair cell via osmosis