Option+H

Option H page 340. (a) 5.3 ( ±  0.3) pmol dm -3  (unit needed) 1 (b) a positive correlation; no data below 280 mOsmol kg –1 ; 1 max (c) after drinking water, blood plasma / solute concentration decreases; plasma ADH concentration decreases; osmoreceptors in the hypothalamus monitor blood solute / blood plasma plasma concentration; impulses passed to ADH neurosecretory cells to reduce / limit release of ADH; drop in ADH decreases the effect of this hormone on the kidneys; blood solute concentration returns to normal; 2 max (d) vomiting / diarrhoea / blood loss; increase salt intake; drink alcohol / coffee; certain drugs / morphine / nicotine / barbiturates; excess sweating / lack of water intake; diabetes as it increases glucose in blood; 2 max ** [6] ** page 343. 1.a) As the rate of bile salt secretion goes up, the rate of flow of bile increases.  b)  Bile salts draw water into the narrow canaliculi (by osmosis) and this increase the flow rate. 2. After the consumption of a meal containing fat. 3. a) Secretin causes an increase in the rate of bile flow;   at all rates of bile salt release/increase caused is uniform.   4.  When concentration of bile salt is zero, there is still flow of bile;   5.  indicating something else was drawing water into the tubes.  page 346    (a) (i) 2.6 (  ±  0.2) nmol mg –1  liver tissue //(units required)// 1    (ii) 6.4 (  ±  0.3) nmol mg –1  liver tissue //(units required)// 1    (b) injection reduces the total glutathione content in liver tissue; by about 45 % / 2.4 nmol mg –1   ; reduced glutathione content is reduced by about 41 % / by 1.8 nmol mg –1   ; smaller proportion of glutathione is oxidized; 2 max    (c) pre-treatment with flaxseed increases glutathione content over control levels; cells exposed to tetrachloromethane with pre-treatment with flaxseed maintained higher glutathione levels than without pre-treatment; so cells would show less damage when exposed to free radicals; hard to evaluate due to short period of investigation; 3 max Page 351: Asthma question (a)225 (±5) 1 (b) decreased for the first four/five months / up to June/July / initially; increased in September / October; decline in November; showed day to day fluctuation; slight increase in May and June / April and May; less variation / plateaus July to August / September; 3 max (c) Simple “ //yes/no” not acceptable//. the data does not support the hypothesis; the increase in asthma admissions does not immediately follow a rise in pollen hospital admissions fall whilst pollen levels remain constant in March to August; the data does support the hypothesis; the main increase in asthma admissions follows a short time after a rise in pollen; 2 (d) inflammation of airways / bronchioconstriction constriction of airways / increased mucus secretion in airways coughing / lack of breath 1 max Page 351 blood gases question (a) 93 % ± 1 % 1 (b) (i) increases by 0.63 mmol l –1   of blood rises from 15.59 to 16.22 mmol I –1 1 (ii) dissolved CO 2 1 (c) CO 2   makes the blood more acidic and the pH drops; pH of venous blood at rest has decreased compared to arterial blood; because the blood is carrying waste CO 2 (from CO  2    cellular respiration) back to lungs for removal; pH of venous blood after exercise has decreased compared to arterial blood; and dropped even further than venous blood at rest; because the blood is carrying more waste CO 2 than normal due to exercise; 3 max
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