B1 2021

Question 1

2.1 Explain the advantage for larger animals of having a specialised system that facilitates oxygen uptake

Answer 1

Larger organisms have smaller SA:Vol ratio
Overcome long diffusion pathway

Question 2

2.2 Suggest how environment conditions resulted in adaptions of systems using Model A rather than Model B
(A: Oxygen uptake through the outside of the body)

Answer 2

Water lowers oxygen partial pressure
So reduces diffusion distance

Question 3

7.5 Suggest and explain two further investigations that should be done before this ADC is tested on human breast cancer patients

Answer 3

To test on healthy volunteers to check for safety
Test in other larger mammals

Question 4

8.1 Describe how a triglyceride molecule is formed

Answer 4

Formed from glycerol and 3 fatty acid molecules
Condensation forming ester bonds between glycerol and 3 fatty acid molecules
Removal of 3 water molecules