Answers · Hormones

Hormones — final check key

Check meaning, not exact wording. These are teaching points, not official Cambridge marks.

1. CK1 · Final check

Model answer. Speed of action: the blink, a nervous reflex, acts within a fraction of a second; the racing heart, caused mainly by adrenaline, builds up more slowly, over seconds to minutes. Duration of effect: the blink is over in well under a second; the racing heart lasts for minutes, while adrenaline stays in the blood.

A full answer includes

I wrote that the blink acts faster, within a fraction of a second.
I wrote that the racing heart is slower to build up, over seconds to minutes.
I wrote that the effect of the blink is shorter.
I wrote that the racing heart lasts longer, for minutes.
I did not write that the racing heart acts faster because the blood reaches everywhere.

Also accept

blink faster and shorter; racing heart slower and longer

Watch for

“The racing heart acts faster, because the blood reaches everywhere.” — A hormone must be released and carried in the blood before it acts: it is slower than a nerve impulse.
“The blink lasts longer, because she keeps blinking.” — Each blink is over in well under a second. The racing heart lasts for minutes.

2. CK2 · Final check

Model answer. (a) The highest heart rate in the table is 112 beats per minute, at 2.5 minutes, so the time to the peak is 2.5 minutes. (b) The resting rate is 72, so within 5 of it means 77 or below. At 12 minutes the rate is 81, still 9 above; at 20 minutes it is 75. So the first time in the table is 20 minutes: a long duration of effect, as hormonal control gives.

Checked automatically

(a) Time to the peak: 2.5 min (within ±0.05 min)
- Common wrong answer 112 : That is the heart rate at the peak. Give the time in the same row.
(b) First time within 5 beats per minute of resting: 20 min (within ±0.1 min)
- Common wrong answer 12 : At 12 minutes the rate is 81, still 9 above the resting rate of 72.
- Common wrong answer 8 : At 8 minutes the rate is 90, far above the resting rate of 72.

A full answer includes

(a) I found the highest heart rate in the table, 112 beats per minute.
(a) I wrote 2.5 minutes.
(b) I worked out that within 5 of the resting rate of 72 means 77 or below.
(b) I wrote 20 minutes.
I did not write 12 minutes: at 12 minutes the rate, 81, is still 9 above the resting rate.

Also accept

(a) 2.5 minutes; (b) 20 minutes

Watch for

“(a) 112.” — That is the heart rate at the peak. The time to the peak is the time in the same row.
“(b) 12 minutes.” — At 12 minutes the rate is 81, which is 9 above the resting rate of 72: not yet within 5.

3. AK1 · Final check

Model answer. A hormone is a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs. Sweat is produced by a gland, so that part fits. But it is not carried by the blood: it flows along a tube onto the skin. And it does not alter the activity of a target organ: it simply evaporates and cools the body. So sweat is not a hormone.

A full answer includes

I wrote that sweat is made by a gland, so that part of the description fits.
I wrote that sweat is not carried by the blood: it flows along a tube to the skin surface.
I wrote that sweat does not alter the activity of a target organ: it cools the body as it evaporates.
I did not write that sweat fails because it is not made by a gland.

Also accept

made by a gland, but not carried by the blood and alters no target organ

Watch for

“Sweat is not a hormone because it is not made by a gland.” — Sweat is made by a gland. The parts that fail are how it travels and what it does.
“Sweat is not a hormone because it is a liquid.” — Being a liquid is not the test. Check how it travels and whether it alters the activity of a target organ.

4. AK2 · Final check

Options as numbered on the pupil sheet: 1 — insulin; 2 — decreases; 3 — stays the same; 4 — adrenaline; 5 — increases.

Model answer. Being chased by a wasp is a fight or flight situation, so the adrenal glands secrete adrenaline. Adrenaline increases the breathing rate, the heart rate and the pupil diameter.

A full answer includes

I matched the hormone to adrenaline.
I matched the breathing rate to "increases".
I matched the heart rate to "increases".
I matched the pupil diameter to "increases".
I did not match the pupil diameter to "decreases".

Also accept

adrenaline; breathing rate, heart rate and pupil diameter all increase

Watch for

“The pupil diameter decreases.” — Adrenaline makes the pupils wider: their diameter increases, letting more light in.
“The heart rate stays the same; the heart only beats more strongly.” — Adrenaline increases the heart rate: the heart beats faster.
“The hormone is insulin.” — Insulin is secreted by the pancreas and does not prepare the body for danger. A fright brings adrenaline from the adrenal glands.

5. AK3 · Final check

Model answer. Adrenaline increases the blood glucose concentration, by making the liver release glucose, and increases the heart rate. More glucose and oxygen reach the muscles, so they can respire faster and release more energy.

A full answer includes

I wrote that it increases the blood glucose concentration.
I wrote that the liver releases the glucose.
I wrote that it increases the heart rate.
I wrote that more glucose and oxygen reach the muscles for respiration.
I did not write that it lowers the blood glucose concentration.

Also accept

blood glucose up; heart rate up; more glucose and oxygen for respiration

Watch for

“It lowers the blood glucose concentration.” — Adrenaline raises it. Insulin lowers it.
“It gives the muscles energy directly.” — Adrenaline carries no energy. The muscles release energy from glucose in respiration.

6. GK1 · Final check

Options as numbered on the pupil sheet: 1 — kidney – adrenaline; 2 — testis – oestrogen; 3 — ovary – oestrogen; 4 — liver – insulin; 5 — pancreas – insulin; 6 — adrenal gland – adrenaline; 7 — testis – testosterone.

Model answer. E, one of the small glands either side of the uterus, is an ovary: oestrogen. F, one of the oval glands in the sac, is a testis: testosterone. G, the long gland between the kidneys, behind and below the stomach, is the pancreas: insulin. H, the small gland on top of a kidney, is an adrenal gland: adrenaline.

A full answer includes

I matched E to ovary – oestrogen.
I matched F to testis – testosterone.
I matched G to pancreas – insulin.
I matched H to adrenal gland – adrenaline.
I did not match H to kidney – adrenaline: H is the small gland on top of the kidney.

Also accept

E ovary – oestrogen; F testis – testosterone; G pancreas – insulin; H adrenal gland – adrenaline

Watch for

“H is the kidney, which secretes adrenaline.” — The line ends on the small gland on top of the kidney, not on the kidney. The kidneys make urine; the adrenal glands secrete adrenaline.
“F is a testis that secretes oestrogen.” — The testes secrete testosterone. Oestrogen comes from the ovaries.
“G is the liver, which secretes insulin.” — The liver is the large organ higher up, and a target of insulin. G is the long gland behind and below the stomach: the pancreas.
“E is an ovary that secretes testosterone.” — The glands beside the uterus are the ovaries, which secrete oestrogen. The glands in the sac are the testes, which secrete testosterone.

7. GK2 · Final check

Model answer. D. Glucagon is secreted by the pancreas, which also secretes insulin.

A full answer includes

I chose row D.
I did not choose row A: the liver is a target of glucagon, not the gland that secretes it.

Also accept

Watch for

“Row A: the liver, and insulin.” — The liver is a target of glucagon and of insulin. Both are secreted by the pancreas.
“Row B: the pancreas, and adrenaline.” — The gland is right, but adrenaline is secreted by the adrenal glands. The pancreas's other hormone is insulin.
“Row C: the adrenal glands, and adrenaline.” — The adrenal glands secrete adrenaline, but not glucagon. Glucagon comes from the pancreas.