B9 - respiration exam questions

Question 1

why did the man’s breathing rate increase when he was running (2 marks)

Answer 1

to get more oxygen (into the blood)
for use in respiration or releasing energy

OR
to remove carbon dioxide
produced in respiration

Question 2

give one measurement that could be taken to show a different affect, other than breathing rate, on the body (1 mark)

Answer 2

any one from
- heart/pulse rate
- depth/volume of breathing
- volume of sweat (allow amount)
- body temperature

Question 3

what is the word equation for aerobic respiration (1 mark)

Answer 3

glucose + oxygen –> carbon dioxide and water

Question 4

where does aerobic respiration take place (1 mark)

Answer 4

mitochondria

Question 5

give 2 uses of energy released in respiration (2 marks)

Answer 5

any 2 from
- movement/muscle contraction
- keeping warm
- active transport
- building larger molecules

allow examples of movement
allow cell division

ignore reference to metabolism unqualified
ignore growth

Question 6

describe 2 differences between aerobic and anaerobic respiration in animals. do not refer to oxygen in your answer (2 marks)

Answer 6

any two from
- anaerobic respiration produces lactic acid AND aerobic does not
allow oxygen debt instead of lactic acid
- aerobic produces carbon dioxide and anaerobic does not
- aerobic produces water and anaerobic does not
- allow anaerobic only occurs in the cytoplasm
- anaerobic RELEASES less energy than aerobic

Question 7

one metabolic reaction is the formation of lipids. name on other metabolic reaction in cells (1 mark)

Answer 7

• respiration
• formation of proteins
• formation / breakdown of glycogen
• breakdown of protein or formation of urea
• photosynthesis or formation of glucose

Question 8

a student made the following hypothesis about the heart rate of smokers and non-smokers during exercise

“during exercise, the heart rate of smokers increases more than the heart rate of non-smokers”

design an investigation that would allow you to test this hypothesis (6 marks)

Answer 8

• two groups of people - smokers and non-smokers
• have at least 5 people in each group or large groups
• get each person to do (named) exercise
• controlled variables:
  same number of people in each group
  same gender
  same age
  same level of activity
  no illnesses/health issues
  same type of exercise
  same time of doing exercise
• record heart rate for each person before and after exercise
• calculate increase in heart rate for each person after exercise
• compare results for each group

Question 9

what is the purpose of a control (1 mark)

Answer 9

to act as a comparison

Question 10

the following equation describes anaerobic respiration in muscle cells.

glucose –> lactic acid

how can you tell from the equation that this process is anaerobic (1 mark)

Answer 10

no oxygen is used

Question 11

exercise cannot be sustained when anaerobic respiration takes place in muscle cells. explain why (2 marks)

Answer 11

muscles become fatigued / stop contracting

because not enough energy is transferred

Question 12

describe how glucose from the small intestine is moved to a muscle cell (2 marks)

Answer 12

glucose is absorbed by diffusion into the bloodstream

the blood delivers glucose to muscles in capillaries

Question 13

compare anaerobic respiration in a yeast cell with anaerobic respiration in an muscle cell (3 marks)

Answer 13

yeast produces ethanol but muscle produces lactic acid

yeast produces carbon dioxide but muscle does not

both release small amounts of energy

ignore both occur without oxygen

Question 14

what does anaerobic mean (1 mark)

Answer 14

without oxygen