Monday 1 June 2020

Question 1

Describe the role of the intercostal muscles and the diaphragm when breathing in.

Answer 1

• intercostal muscles contract;
• the diaphragm flattens;
• ribs move out;
• increases the volume in the thorax;
• decreases pressure in the thorax/lung.

Question 2

Acacia flowers produce a chemical that repels ants.
Suggest two advantages for the acacia plant of producing this chemical.

Answer 2

ants wont eat polinators;
ants wont destroy pollen

Question 3

what does anerobic respiration in yeast do

Answer 3

produce alchohol

Question 4

The oxygen and nitrogen are sterilised to remove micro-organisms.
Suggest why micro-organisms need to be removed from these gases.

Answer 4

• micro-organisms may compete for glucose;
• they might kill the yeast;
• cause the speed of reaction to change;
• killing them removes any pathogens

Question 5

Alkaptonuria can prevent heart valves from working properly.
Explain how this would affect the ability of a person to exercise.

Answer 5

reduced ability to exercise;
less oxygen coming from lungs;
less oxygen the body;
less respiration;
less energy;
more anaerobic respiration; lactic acid pressent.

Question 6

State the five chemical elements that could be present in protein.

Answer 6

CHONS

• carbon
• hydrogen
• oxygen
• nitrogen
• sulphur

Question 7

test for fats

Answer 7

add ethanol - add water and look for white emulsion

Question 8

name a carbohydrate that can be found in faeces

Answer 8

• cellulose
• glucose
• starch

Question 9

What is the cell wall made of in a plant cell?

Answer 9

Cellulose

Question 10

what is required to break down cellulose?

Answer 10

Cellulase (an enzyme)