Biology · May / June 2024 · Paper 41 · Question 1

any two from:

(fish has)

fins / no legs / no limbs ;

scales / scaly skin ;

operculum ;

deeper body / larger ratio of depth to length ;

reptiles / birds ;

total of four from:

similarities to max 3:

1

both have, heart / blood vessels / capillaries / arteries / veins ;

2

(heart with) one ventricle / no (visible) septum ;

3

both have valves (in the heart) ;

4

blood flows through atrium and then ventricle ;

5

no (visible) separation of oxygenated and deoxygenated blood ; differences to max 3:

6

fish have capillaries in gills and amphibians have capillaries in lung and skin ;

7

fish have a single circulatory system and amphibians have a (incomplete) double circulatory system ;

8

fish has a 2-chambered heart / amphibian has 3-chambered heart ; 9

amphibians have two atria / fish have one atrium ;

10 amphibians have a separate circuit to the, gas exchange surface / AW ;

11 fish have one valve (in heart) / amphibians have three valves (in heart) ;

any three from:

1

ref. to double (rather than single) circulatory system ;

2

(allows / maintains) high(er) blood pressure (to tissues / body) ; 3

for faster / more efficient, transport, (named) substances / blood ; 4

supports fast(er), metabolism / respiration ;

5

allows lower pressure to lungs ;

6

(lower pressure) allows more time for, gas exchange / absorption of oxygen ;

7

prevents damage to lungs / AW ;

8

AVP ;

total of four from:

arteries to max 3

1

idea of arteries have thick walls to, withstand / cope with / deal with, high pressure ;

2

arteries have (thick layer of) elastic tissue to, stretch / recoil (due to the changing pressure) ;

3

arteries have (thick layer of) muscular tissue to change pressure ; 4

arteries have narrow(er) lumen to maintain high pressure ;

5

veins have valves to prevent backflow of blood (due to low pressure) ; 6

veins have, thin walls / large lumen, to provide less resistance to blood flowing at low pressure / allow large volumes of blood / AW ;

7

veins have thin walls so blood is moved by contraction of (surrounding) muscles / AW ;

name of the artery that brings

name of the organ

blood to the organ

lungs

pulmonary (artery) ;

kidney ;

renal artery

liver

hepatic (artery) ;