OCR GCSE Biology A: Endocrine system, thyroxine, adrenaline and menstrual cycle (J247) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover statements B3.2a to B3.2d of module B3.2 in OCR GCSE (9-1) Gateway Science Biology A (J247), specification Version 4.0 (August 2026), for first assessment in 2018. Questions labelled Higher Tier only draw on B3.2b (thyroxine and adrenaline) or B3.2d (interactions of FSH, LH, oestrogen and progesterone), which are in bold in the specification. The other questions suit both tiers. Learn the content from the study guide or the revision notes. Course pages: OCR GCSE Biology hub | checklist.

Questions

1. State two differences between control by hormones and control by the nervous system. [2]

2. Name the gland that produces each hormone. (a) Oestrogen [1] (b) Testosterone [1] (c) FSH [1]

3. Hormones are released into the blood and travel all around the body, but each hormone affects only certain cells. Explain why. [3]

4. (Higher Tier only) A student’s resting heart rate is 64 beats per minute. When a door slams behind her it rises to 104 beats per minute. (a) Work out by what percentage her heart rate has risen. [2] (b) Explain how the release of adrenaline helps her to run away. [2]

5. (Higher Tier only) A volunteer takes a tablet that raises blood thyroxine. Thyroxine was measured in arbitrary units.

Hour after tablet	0	2	4	6	8	10
Thyroxine (units)	50	74	66	58	52	50

(a) Calculate the percentage increase in thyroxine between hour 0 and hour 2. [2] (b) Calculate the mean rate at which thyroxine fell between hour 2 and hour 10. [2] (c) Explain how the data show negative feedback. [2]

6. (Higher Tier only) Describe how negative feedback brings blood thyroxine back to normal when the level rises above normal. [3]

7. Describe the roles of FSH, oestrogen and progesterone in the female menstrual cycle. [4]

8. (Higher Tier only) The table shows hormone levels (arbitrary units) for one cycle.

Day	3	6	9	12	14	15	18	21	24	27
FSH	9	10	8	5	6	4	2	2	2	6
LH	4	4	5	12	35	8	4	4	4	4
Oestrogen	25	40	90	200	170	110	90	130	150	50
Progesterone	2	2	2	2	3	8	20	26	24	6

(a) State the day on which LH was highest. [1] (b) Calculate the percentage increase in oestrogen from day 3 to day 12. [2] (c) Suggest on which day ovulation most likely happened, and give a reason. [2] (d) Explain the rise in progesterone between day 15 and day 21. [1]

9. State where testosterone is made, one function of testosterone, and one function of oestrogen at puberty. [3]

10. (Higher Tier only) A woman’s egg is not fertilised. Explain how changes in hormone levels cause menstruation and then start the next cycle. [5]

11. (Higher Tier only) Hormone levels were measured in a woman who had no bleeding by day 32.

Day	20	24	28	32
Progesterone (units)	26	28	29	30
FSH (units)	2	2	2	2

(a) Describe how the progesterone pattern differs from the pattern in a cycle in which the egg is not fertilised. [2] (b) Calculate the percentage change in progesterone from day 20 to day 32. Give your answer to 2 significant figures. [2] (c) Suggest an explanation for the absence of bleeding. [2] (d) Explain why FSH stays low. [2]

12. A student says: “A fertilised egg can only embed when the lining of the uterus is breaking down.” (a) Explain why the student is wrong. [3] (b) The lengths of five of one woman’s cycles were 27, 29, 28, 30 and 26 days. Calculate the mean cycle length. [2]

Answers

1. Hormones travel in the blood, nerves use electrical impulses [1]. Hormonal responses are slower and longer lasting (or hormones can affect a wider area) than nervous responses [1]. [2] Examiner insight: A comparison needs both sides, so “hormones are slow” alone is weaker than “hormones are slower than nerve impulses”.

2. (a) Ovaries (ovary) [1] (b) Testes [1] (c) Pituitary gland [1] Examiner insight: Name the gland, not the whole system; “reproductive organs” is too vague to credit.

3. The blood carries each hormone to all tissues [1]. Only target cells have receptors that fit that hormone [1]. Cells without the receptor do not respond [1]. [3] Examiner insight: Answers that say only “it goes to the target organ” miss the explanation; you need the receptor point.

4. (a) 104 - 64 = 40 [1]; 40 / 64 x 100 = 62.5% [1] (b) Adrenaline increases heart rate so more blood carrying oxygen and glucose reaches the muscles [1]; the muscles can respire faster to release energy for running [1] Examiner insight: In a percentage calculation, show the change divided by the starting value; a correct figure with working is easier to credit than a bare answer.

5. (a) 74 - 50 = 24 [1]; 24 / 50 x 100 = 48% [1] (b) Fall from hour 2 to hour 10 = 74 - 50 = 24 units [1]; 24 / 8 = 3 units per hour [1] (c) The level rose above normal (50) and then fell back to 50 [1]; a rise caused a response that reverses it, so less thyroxine was released and the level returned to normal [1] Examiner insight: For a mean rate, divide by the time interval and include the unit; for the explanation, quote values from the table.

6. The raised thyroxine level is detected [1]; less thyroxine is released from the thyroid [1]; the level falls back to the normal range [1] [3] Examiner insight: Say the response reverses the change; “the body balances it” is too vague to show negative feedback.

7. FSH makes an egg mature in the ovary [1] and stimulates the ovary to make oestrogen [1]; oestrogen thickens (repairs) the lining of the uterus [1]; progesterone maintains the lining [1] [4] Examiner insight: Four marks means four separate points; give each hormone a different job rather than repeating “it controls the cycle”.

8. (a) Day 14 [1] (b) (200 - 25) = 175 [1]; 175 / 25 x 100 = 700% [1] (c) Ovulation is most likely on or just after day 14 [1] because the LH surge triggers ovulation [1] (d) After ovulation the empty follicle makes progesterone, which rises to keep the lining thick [1] Examiner insight: A reason that quotes the LH value (35 units on day 14) shows you have used the data, not just remembered the fact.

9. Made in the testes [1]. Any one: stimulates sperm production; brings about male puberty changes (such as voice deepening or facial hair) [1]. Oestrogen at puberty: brings about female changes such as breast development (or helps start the menstrual cycle) [1] [3] Examiner insight: “Sex hormone” on its own describes neither function; name a specific change.

10. The egg is not fertilised, so the empty follicle breaks down and progesterone falls [1]; oestrogen also falls [1]; the lining can no longer be maintained and breaks down (menstruation) [1]; FSH is no longer inhibited so its level rises [1]; a new egg starts to mature in a follicle and the cycle restarts [1] [5] Examiner insight: Strong answers run in order of cause and effect: what falls, what that allows, then what rises.

11. (a) Progesterone stays high (rises from 26 to 30) up to day 32 [1] instead of falling after about day 23 [1] (b) (30 - 26) = 4 [1]; 4 / 26 x 100 = 15.38…%, so 15% (2 significant figures) [1] (c) Progesterone is maintaining the lining so it does not break down [1]; this suggests a fertilised egg has embedded in the lining [1] (d) High progesterone inhibits FSH [1]; so no new egg matures [1] Examiner insight: When asked for 2 significant figures, show the unrounded value first and then round.

12. (a) Ovulation happens at about day 14 when the lining is already thick [1]; a fertilised egg embeds in this thick lining [1]; the lining breaks down at menstruation if no egg embeds, so the student has the timing the wrong way round [1] (b) 27 + 29 + 28 + 30 + 26 = 140 [1]; 140 / 5 = 28 days [1] Examiner insight: Link the timing of ovulation to the state of the lining; naming the hormones alone does not answer a “why” question.

Where marks are usually lost

• Saying hormones travel along nerves or in tubes, rather than in the blood.
• Giving “only the target organ gets it” and leaving out receptors.
• Describing negative feedback without saying the response reverses the change.
• Working out a percentage change against the final figure rather than the starting figure.
• Leaving out units, such as units per hour for a rate.
• Mixing up FSH and LH, or saying both “make the egg”.
• Writing that progesterone causes bleeding, when its fall is what allows the lining to break down.
• Describing a graph or table without quoting any values and days.
• Rounding to the wrong number of significant figures, or rounding before the final step.

Next steps

• Re-read the revision notes and the study guide.
• Course pages: OCR GCSE Biology hub and checklist.
• Find your weak spots with the free 10-minute diagnostics.
• Want a teacher to go through your answers? Book a free trial class.

Official syllabus

OCR GCSE (9-1) Gateway Science Biology A (J247), specification Version 4.0 (August 2026), for first assessment in 2018, published by OCR. Module B3.2, statements B3.2a to B3.2d.