Common Test 2 Marker's Report (sec 3 - 2007)

Biology 5100 Marking Scheme/Marker’s Report Sec 3 Common Test #2 2007 Q 11 (a)(i) (a)(ii)

Marking Scheme Urine Sweat

(a)(iii) Water vapour in expired air (a)(iv) With undigested food/faeces / A/W. (b)

During a cross-country run / after vigorous exercise. Accept any possible alternatives given; Less urine produced and amount of water reabsorbed by kidneys would increase.

Q 12 (a)

Marking Scheme 3 The bicuspid/tricuspid valves are pushed open. 7 Blood enters the arteries. 1 Blood enters the atria from the veins. 4 Blood is pushed into the ventricles. 2 The atria contract. 6 The semilunar valves are pushed open. 5 The ventricles contract.

(b)

5, 6, 7 [1]; (c)(i)

2, 3, 4 [1];

Marks [1] [1] [1] [1] [2]

Marks [1]

R: missing number(s) for each diagram.

[3]

A: Ref. To oxygenated blood being pumped to all parts of body/body tissues under high pressure. Well answered by pupils. A: Ref. to lower pressure to pump blood from atrium to ventricle.

[2]

1 [1].

Left side; Highest level of pressure measured.

(c)(ii)

Comments R: Urea. R: Water vapour A: Perspiration R: Respiration/Expiration. R: unused food/Urination/Urine/Faeces. A: Dehydration. R: Drinking more water/Urine becomes more concentrated. No marks for describing2nd marking point without specifying situation. Comments R: wrong sequence/missing number(s) given.

Line 1: Blood pressure in left atria; Negative pressure when ventricle is in systole and pressure rises as it fills with blood from pulmonary vein; (A/W) Line 2: Blood pressure in left ventricle; High pressure necessary because blood is being pumped out to the rest of the body;

Well answered by pupils.

Line 3: Blood pressure in aorta; High as that of the ventricle but does not drop so much

R: Pressure lower as blood flows further from heart.

[6]

due to elastic walls of the arteries to help maintain the pressure. (A/W)

(d)

Q 13

P: Systole; Q: Diastole; R: Semilunar valves open; S: Bicuspid/tricuspid valves open. Marking Scheme (Inhalation) External intercostals muscles contract, internal intercostals muscles relax; Ribs are raised upwards and outwards;

(Distance not reflected in graph given) Award correct explanation mark if chamber name(s) are correct but (left) location not specified in answer. Pupils give multiple answers on each blank. Comments R: References to expansion of muscles/Expansion of ribcage.

At the same time, diaphragm muscles contract and Diaphragm flattens;

I: Adaptations of alveoli for gaseous exchange/Details on gaseous exchange were given.

Air pressure in lungs decreases as thoracic cavity enlarges;

R: sp: sterum/diagphragm Extercostal muscles.

Air rushes in for gaseous exchange to occur;

± sp: intercoastal muscles.

(Exhalation) Internal intercostals muscles contract, external intercostals muscles relax; Rib cage swings downwards and inwards; At the same time, diaphragm muscles relax and diaphragm arches upwards/diaphragm becomes domeshaped; Air pressure in lungs increases as thoracic cavity decreases in volume; Air is forced out of lungs.

[2]

Marks [10]