Respiration

Question 1

what does it mean when mammals have a double circulatory system

Answer 1

• heart pumps blood in a double circuit system when in the first circuit deoxygenated blood taken to lungs for oxygenation and in the second circuit pumps oxygenated blood to organs to deliver oxygen to body cells

Question 2

describe the path heart pumps blood

Answer 2

in the right atrium heart receives deoxygenated blood from vena cave
heart contracts and blood is pushed into right ventricle and pumps into lungs through pulmonary artery
blood travels pass alveoli for gas exchange
and returns to heart via pulmonary vein where oxygenated blood from lungs is received
heart contracts and moved into left ventricle and pumped out whole body through arota

Question 3

why is the walls in the left ventricle thicker and name another feature of it

Answer 3

because more muscle to pump blood around body at high pressures
and valves to prevent back flow of blood

Question 4

what is the formula for cardiac output

Answer 4

heart rate x stroke volume

Question 5

what is respiration

Answer 5

process of transferring energy from the breakdown or organic compounds such as glucose and this is exothermic

Question 6

what is the energy from respiration needed for

Answer 6

• metabolic processes such as making larger molecules from smaller one
• contracting muscles
• maintaining body temperature

Question 7

what is aerobic respiration

Answer 7

when there is plenty oxygen, complete breakdown of glucose producing energy

glucose + oxygen = carbon dioxide + water

Question 8

what is anaerobic respiration

Answer 8

• when you do vigorous exercise so body cannot supply enough oxygen to muscles for aerobic respiration hence heart rate and breathing rate is increased

anaerobic is less efficient and less energy and lactic acid produced

Question 9

what does anaerobic respiration in plants produce

Answer 9

ethanol and carbon dioxide

Question 10

what is oxygen debt

Answer 10

The amount of oxygen required to break down the lactic acid that has built up

Question 11

how can you measure rate of respiration

Answer 11

• measure amount of oxygen consumed by organism in given time to calculate rate
• add soda lime granules to two test tubes, soda lime absorbs CO2 produced by respiring woodlice
• a ball of cotton wool placed on soda lime, and glass beads of same mass in control tube and woodlice on cotton wool
• respirometer and syringe set fluid in manometer
• placed in water bath to 15’C
• decrease in volume as woodlice take up oxygen hence reduces pressure
• coloured liquid in manometer move towards woodlice test tubes
• distance moved used to calculate volume of oxygen intake
• repeat with different temperatures