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One chapter, four questions

The whole zoology set from the test — all four from Human Reproduction, grouped by sub-topic. Each is rebuilt with what was given, what was asked, the concept behind it, the steps in full, the fastest route through, and a figure.

4
Questions lost
2
Attempted, wrong
2
Left blank
16
Marks at stake

All four come from Human Reproduction, so they are grouped here by sub-topic. Three concern one hormone or another; the fourth, colostrum, reaches across into Human Health and Disease.

The smallest set of the four subjects, and the cleanest. Every one of these four questions is answered by knowing where a hormone comes from and what it does. Neither wrong answer was a gap in the facts; both were failures to connect two facts already known.

Chapters in this paper  —  red = wrong · amber = blank · green = correct

Human Reproduction

4 questions · 2 wrong · 2 blank

Q149Q166Q169Q178

Chapter

Human Reproduction

Menstrual cycle, pregnancy, parturition and lactation  ·  4 questions · 2 wrong · 2 blank

Menstrual cycle and pregnancy

2 questions · 1 wrong · 1 blank
Q149 Assertion–reason · no menstruation in pregnancy Marked wrong

Assertion (A): During pregnancy, there is no menstruation.
Reason (R): During pregnancy, progesterone and oestrogen levels remain elevated.

the loop that keeps the endometrium intactPregnancyhCG fromthe placentaCorpus luteumpersistsProgesterone +oestrogen stay highnegative feedback→ FSH and LH suppressedendometrium ismaintained, not shedno follicle matures · no menstruationR is not a separate fact —it is the mechanism behind A
  • KEYBoth (A) and (R) are true and (R) is the correct explanation of (A).
  • MARKEDBoth (A) and (R) are true but (R) is not the correct explanation of (A).
  •  (A) is true but (R) is false.
  •  Both (A) and (R) are false.
Given
  • Assertion: menstruation stops during pregnancy.
  • Reason: progesterone and oestrogen stay elevated during pregnancy.
Asked
Whether both statements are true, and whether R explains A.
Concept to use
Menstruation is not an event that happens — it is what happens when progesterone withdrawal occurs. In a normal cycle the corpus luteum degenerates around day 26, progesterone crashes, and the endometrium loses its hormonal support and is shed. In pregnancy hCG from the developing placenta keeps the corpus luteum alive, so progesterone and oestrogen never fall. No withdrawal means no shedding. High progesterone also suppresses FSH and LH by negative feedback, so no new follicle matures and no new cycle begins.
Formula to use
Menstruation ⇔ progesterone falls  →  sustained progesterone ⇒ endometrium maintained, no menses
Baby steps
  1. Is A true? Yes — menstruation ceases for the whole of pregnancy. A missed period is the first common sign of it.
  2. Is R true? Yes — hCG rescues the corpus luteum, which continues secreting progesterone; the placenta takes over from about the third month, keeping both hormones high throughout.
  3. Does R explain A? Apply the removal test: if progesterone were not elevated, the endometrium would lose support and be shed — menstruation would occur. So the elevated hormones are not a coincidental accompaniment; they are the cause.
  4. The high progesterone also blocks FSH and LH release, so no follicle develops and no cycle can start.
  5. Both true, and R is the correct explanation.
Answer
Both (A) and (R) are true and (R) is the correct explanation of (A).
Shortcut
The removal test settles nearly every assertion–reason item in one line: if R were false, would A still hold? Here, remove the elevated progesterone and menstruation resumes — so R is the explanation, not a bystander.
Where it went wrong
Both statements were accepted as true but the causal link was denied. The two facts probably felt like separate things learned from separate paragraphs. The habit to build: after marking both true, do not stop — ask what would happen if R were removed. Two true statements sitting side by side in your notes can still be cause and effect.
Q169 Progesterone across the menstrual cycle Not attempted

Select the correct statement about progesterone level during the menstrual cycle.

progesterone stays low until ovulation, then climbs07142128day of cyclehormonelevelovulationmenstrualfollicularlutealprogesteroneoestrogen
  •  Remains high during the follicular phase and falls markedly during the luteal phase.
  •  Remains low during the follicular phase but rises markedly during the ovulatory phase.
  •  Remains high during menstruation and declines following ovulation.
  • KEYRemains low during the follicular phase but rises markedly during the luteal phase.
Given
  • The 28-day menstrual cycle, divided into menstrual, follicular, ovulatory and luteal phases.
Asked
The correct description of progesterone levels.
Concept to use
Progesterone comes almost entirely from the corpus luteum, and the corpus luteum does not exist until after ovulation — it forms from the ruptured follicle. So progesterone cannot be high before ovulation. Its whole story follows the corpus luteum: absent before ovulation, rising through the luteal phase, peaking around day 21, then falling as the corpus luteum degenerates — and that fall triggers menstruation. Oestrogen is the mirror image, peaking just before ovulation from the growing follicle.
Formula to use
Corpus luteum forms after ovulation → progesterone low in follicular phase, high in luteal phase, peak ≈ day 21
Baby steps
  1. Menstrual phase (days 1–5): the previous corpus luteum has already degenerated, so progesterone is at its lowest. Its withdrawal is what caused the bleeding.
  2. Follicular phase (days 1–13): the follicle grows and secretes oestrogen. There is no corpus luteum yet, so progesterone stays low.
  3. Ovulation (day 14): triggered by the LH surge. Progesterone is only just beginning to rise — it does not spike here.
  4. Luteal phase (days 15–28): the ruptured follicle becomes the corpus luteum, which secretes progesterone strongly. Levels rise markedly and peak around day 21.
  5. If no fertilisation occurs the corpus luteum degenerates, progesterone collapses, and menstruation begins — closing the loop.
  6. Only the fourth option matches: low in follicular, high in luteal.
Answer
Remains low during the follicular phase but rises markedly during the luteal phase.
Shortcut
Anchor progesterone to its source and the question answers itself: no corpus luteum, no progesterone. Since the corpus luteum exists only after ovulation, any option putting progesterone high before ovulation — or falling after it — is wrong on sight. That kills three of the four options without recalling a single number.
Option 2 is the near-miss designed to catch a rushed reader: it correctly says progesterone is low in the follicular phase, then attaches the rise to the ovulatory phase instead of the luteal. It is LH that surges at ovulation, not progesterone. Read to the end of every option in this topic — the first half is often correct.

Parturition

1 question · 1 blank
Q178 Pitocin — which hormone Not attempted

Doctors inject Pitocin to induce or augment the delivery of a baby. Pitocin is a synthetic preparation of

the only major positive feedback loop in the syllabusFoetal head pusheson the cervixPosterior pituitaryreleases oxytocinUterine musclecontracts harderCervix stretchesfurthereach turn makesthe next one strongerPitocin is synthetic oxytocin — it starts the loop from outside
  •  prolactin
  • KEYoxytocin
  •  progesterone
  •  thyroxine
Given
  • Pitocin is used clinically to induce or strengthen labour.
Asked
Which hormone Pitocin is a synthetic version of.
Concept to use
Labour is driven by oxytocin from the posterior pituitary, acting on uterine smooth muscle. It is the textbook example of positive feedback: the foetal head presses on the cervix, the stretch triggers oxytocin release, oxytocin strengthens the contraction, which pushes the head harder against the cervix — each turn amplifying the next until delivery. Giving synthetic oxytocin starts or reinforces that loop from outside.
Formula to use
Cervical stretch → oxytocin → stronger uterine contraction → more stretch  (positive feedback)
Baby steps
  1. Identify the job: inducing or strengthening uterine contractions.
  2. Oxytocin from the posterior pituitary causes uterine contraction — and also milk ejection during breastfeeding. It matches. ✓
  3. Prolactin from the anterior pituitary drives milk production, not contraction. The two lactation hormones are easily swapped — prolactin makes milk, oxytocin releases it.
  4. Progesterone does the opposite: it keeps the uterus quiet through pregnancy. Its fall near term helps permit labour.
  5. Thyroxine governs basal metabolic rate and has no role in labour.
  6. Answer: oxytocin.
Answer
oxytocin
Shortcut
The trade name carries the answer: Pitocin → pituitary, -ocin → oxytocin. Where a drug name is offered, check whether it echoes the hormone before reasoning further.
Keep the two milk hormones straight, since they are asked together constantly: prolactin produces milk, oxytocin ejects it. Oxytocin therefore appears twice in this chapter — in labour and in the milk let-down reflex — and both are positive feedback loops.

Lactation

1 question · 1 wrong
Q166 Colostrum — which kind of immunity Marked wrong

Colostrum is especially important for the newborn because it is rich in

which way round is colostrum?ACTIVE immunitybody is given an antigenantigen entersbody makes its own antibodiesslow to start · long lastingPASSIVE immunitybody is given ready-made antibodiesantibody arrivesprotection is immediatefast · temporarycolostrum carries IgA antibodies→ passive, and immediate
  • MARKEDantigens that induce active immunity
  • KEYantibodies that provide passive immunity
  •  antibiotics that destroy pathogens
  •  enzymes that digest milk proteins
Given
  • Colostrum — the yellowish fluid secreted in the first few days after childbirth.
Asked
What colostrum is rich in, and what kind of immunity it confers.
Concept to use
Two distinctions decide this. Antigen versus antibody: an antigen is the foreign marker that provokes a response; an antibody is the protein the body makes to neutralise it. Active versus passive: if the body is given an antigen and manufactures its own antibodies, that is active immunity — slow to develop but long-lasting. If ready-made antibodies are handed over from outside, that is passive immunity — immediate but temporary. A newborn cannot wait weeks to build its own defences, so it is given the finished product.
Formula to use
Antigen in → body makes antibodies → ACTIVE  |  antibodies given → PASSIVE
Baby steps
  1. Colostrum is rich in immunoglobulin A (IgA) — these are antibodies, already assembled by the mother.
  2. The newborn does not manufacture them; it simply receives them. So the immunity is passive.
  3. Check the other options. “Antigens inducing active immunity” reverses both halves — wrong molecule and wrong type of immunity.
  4. “Antibiotics” are chemicals produced by microorganisms and used as drugs; the body does not secrete them in milk.
  5. “Enzymes that digest milk proteins” describes a digestive function, not the immunological importance the question asks about.
  6. Answer: antibodies that provide passive immunity.
Answer
antibodies that provide passive immunity
Shortcut
Anything handed over ready-made is passive — colostrum, placental IgG crossing to the foetus, and antitetanus or antivenom serum all sit in this box. Anything that makes the body do the work is active — infection and vaccination. Sorting a new example into “given” or “made” answers the question every time.
Where it went wrong
The chosen option got both halves backwards at once, which suggests the antigen/antibody pair and the active/passive pair are being stored as loose vocabulary rather than as a linked chain. Fix them together in one sentence: antigen provokes, antibody protects; made by me is active, given to me is passive. Note also that this is the one Human Reproduction question that borrows from Human Health and Disease — cross-chapter items are easy to under-prepare.

What the four have in common

Four questions is a small sample, but the shape of the two errors is specific enough to be worth naming.

1 · Facts known separately, not joined — Q149
Both statements were correctly marked true; only the causal link was denied. But menstruation is progesterone withdrawal — sustained progesterone is not something that merely accompanies pregnancy, it is the reason the endometrium is not shed. Fix: after marking both parts of an assertion–reason true, run the removal test — if R were false, would A still hold? This same test also decides Q97 and Q128 in the botany paper, both of which were missed or skipped. Across the three assertion–reason questions in this test, the answer was “R is the correct explanation” every time.

2 · A paired definition reversed on both halves — Q166
The chosen answer swapped antigen for antibody and active for passive simultaneously. Getting both backwards together suggests the two pairs are stored as loose vocabulary rather than as a chain. Fix: one sentence — antigen provokes, antibody protects; made by me is active, given to me is passive. Then sort any new example by asking only whether it was given or made.

3 · The blanks were the two easiest questions in the set
Q178 is a one-word recall, and the drug name Pitocin contains the answer. Q169 is settled by a single anchor — no corpus luteum, no progesterone — which kills three options instantly. This now holds across all four subjects: the unattempted questions are consistently not the difficult ones.

Four anchors that cover the whole set

The correct option is marked KEY and the option selected in the test is marked MARKED; questions with no marked option were left unattempted. All figures have been drawn fresh for these notes; the hormone curves are schematic and show relative levels and timing, not absolute concentrations.