Diversity in animal cells 2.6.4

Question 1

What is differentiation?

Answer 1

When a cell becomes specialised to carry out a particular job/function

Question 2

Name 3 categories of differentiation

Answer 2

• Change number of particular organelle e.g. muscle cell
• Change the shape of the cell e.g. root hair cell
• Change some of the contents of the cell e.g. RBC

Question 3

Which organism has a larger surface area:volume ratio - mouse or polar bear

Answer 3

The mouse, as more cells are exposed to the environment - which allows for effective exchange of substances.

Question 4

How is an erythrocyte specialised for its function?

Answer 4

• Biconcave shape - increases their surface area to volume ratio
• No nucleus - more space for haemoglobin and gas substances
• Flexible - able to squeeze through narrow capillaries

Question 5

How is a neutrophil specialised for its function?

Answer 5

• Multi-lobed nucleus - making it easier for them to squeeze through small gaps to get to the site of infections.
• Granular cytoplasm which contains many lysosomes, that contain lysozymes used to attack pathogens.

Question 6

How are sperm cells adapted to their function?

Answer 6

• Have a flagellum, allowing more mobility
• Contain many mitochondria, supplying energy they need to swim
• Acrosome on the head which contains digestive enzymes, which are released to digest the protective layers around the ovum.

Question 7

Why do many cells become specialised?

Answer 7

Many multi-cellular cells have to become specialised as their surface area to volume ratio is too small - meaning they cannot perform all their cellular functions.