2.3 Metabolic Rate

Question 1

Define ‘Metabolic Rate’

Answer 1

Quantity of energy used in a given period of time

Question 2

What three things can be used to measure metabolic rate?

Answer 2

Oxygen consumption
Carbon Dioxide output
Heat energy output

Question 3

Describe a ‘Respirometer’

Answer 3

Sealed unit with a known volume of air
Contains NaOH to absorb Co2
Organism breathes and uses up oxygen, and releases Co2
Total volume of air decreases
Coloured liquid in capillary tube moves upwards to fill space

Question 4

What is ‘Basal Metabolic Rate’?

Answer 4

Metabolic rate at rest

Question 5

How can Oxygen consumption be measured?

Answer 5

Respirometer

Question 6

How can Carbon Dioxide Output be monitored?

Answer 6

CO2 monitors

Question 7

How can heat energy be monitored?

Answer 7

Thermometer

Question 8

What does high metabolic rate require?

Answer 8

Efficient delivery of Oxygen to cells

Question 9

Describe the circulatory systems of mammals

Answer 9

Complete Double

Question 10

Describe the heart structure of fish

Answer 10

1 atrium, 1 ventricle

Question 11

Describe the gas exchange system in birds

Answer 11

Very efficient
Parabronchi, keeps air flowing in one direction
Able to extract more oxygen
Fresh air to posterior air sac
Passes through parabronchi to front air sac (stale)

Question 12

Describe the circulatory system of amphibians

Answer 12

Incomplete Double

Question 13

Describe the heart structure of reptiles

Answer 13

2 atrium

1 ventricle

Question 14

What minimises the mixing of blood in amphibians/reptiles?

Answer 14

Timings of contractions of hearts

Question 15

Describe the circulatory system of fish

Answer 15

Complete Single

Question 16

Describe the heart structure of mammals and birds

Answer 16

2 atria, 2 ventricles

Question 17

Describe a disadvantage of the fish circulation system

Answer 17

Loss of pressure as blood passes through gills

Question 18

Describe a feature of reptile and amphibian circulation

Answer 18

Mixing of oxygenated and deoxygenated blood

Question 19

What are two advantages of the mammal circulation system?

Answer 19

• Pressure is maintained

- No mixing of different types of bloods

Question 20

Describe the amphibian gas exchange system

Answer 20

Buccal Cavity - before the lung, forces air into the lung

Exchange gases through the moist skin

Question 21

Describe the similarities in reptile/mammalian gas exchange systems

Answer 21

Both have a highly branched system containing air sacs

Question 22

What is an advantage of the parabronchi gas exchange system>

Answer 22

• Able to extract more oxygen

- Keep air flowing in one direction

Question 23

Why do birds require an efficient delivery of oxygen to cells?

Answer 23

Because they have a high metabolic rate due to lots of flying and activity during the day

Question 24

Describe a human physiological adaptation to high oxygen niches

Answer 24

• Increased red blood cells
• Increased haemoglobin
• Increased breathing rate

Question 25

What do the adaptations of humans at high altitudes allow for?

Answer 25

Increased oxygen carrying capacity of the blood, to maintain high metabolic rate needed

Question 26

Describe a deep water physiological adaption

Answer 26

Seals

• Slow down their heart rate
• Collapse their lungs

Question 27

Why do seals slow down their heart rate when going into deep water?

Answer 27

To conserve oxygen and allow them to stay submerged for longer periods of times

Question 28

Why do seals collapse their lungs when diving?

Answer 28

Decrease their buoyancy allowing them to sink faster, conserving energy for hunting

Question 29

What is VO2 Max?

Answer 29

Maximum Oxygen Uptake during strenuous exercise

Question 30

How can VO2Max be used as a measure of human fitness?

Answer 30

Higher the V02 max - fitter the individual

V02 Max is reached when oxygen uptake stays steady even when workload increases