Hormones in human reproduction & Contraception — AQA GCSE Biology

SPEC 4.5.3.4 & 4.5.3.5 • PAPER 2 • ⭐ PRIORITY

Hormones in Human Reproduction

The four named menstrual cycle hormones, how they interact, and the seven named contraception methods AQA expects you to evaluate.

Two Mistakes That Cost Marks Every Year

Examiner reports flag the same two failure points on this topic, regardless of how questions are framed:

Failure Point 1 — Source Confusion

Students put oestrogen at the pituitary, or FSH at the ovary. Mark schemes accept the named source only. Two glands, four hormones — get the pairing wrong and the answer voids.

Failure Point 2 — Direction of Cause

Examiners repeatedly note that students suggest a "direct link" between FSH and a downstream effect (e.g. breast development). The mark scheme wants the chain: FSH stimulates oestrogen secretion → oestrogen causes the effect. Skipping the intermediate hormone or reversing direction loses marks.

In the next 10 minutes, you'll know the four hormones, their sources, their interactions, and how the seven contraception methods exploit them.

By the End of This Lesson

Five outcomes — all on Paper 2. HT-only items are flagged in colour throughout.

Objective 1

Describe the role of oestrogen and testosterone as the main reproductive hormones at puberty.

Objective 2

Name the four hormones in the menstrual cycle (FSH, LH, oestrogen, progesterone) and state the role and source of each.

Objective 3 — HT only

Explain the interactions of FSH, oestrogen, LH and progesterone in the control of the menstrual cycle.

Objective 4 — HT only

Extract and interpret data from graphs showing hormone levels during the menstrual cycle.

Objective 5

Describe and evaluate the seven named hormonal and non-hormonal methods of contraception.

Puberty & The Main Reproductive Hormones

At puberty, reproductive hormones cause secondary sex characteristics to develop. Two hormones do the heavy lifting — one per sex.

Female — Oestrogen

The main female reproductive hormone. Produced by the ovary. At puberty, eggs begin to mature and one is released approximately every 28 days — this release is called ovulation.

Male — Testosterone

The main male reproductive hormone. Produced by the testes. Its role is to stimulate sperm production.

Spec Phrasing

The spec uses the word ovulation for the release of the egg. Mark schemes credit "ovulation" or "release of the egg" — but the named term is preferred.

The Four Menstrual Cycle Hormones

This table is the foundation for every question on this topic. Memorise source and role for each of the four hormones.

HormoneSource (gland)Main role

FSH (follicle stimulating hormone)PituitaryCauses maturation of an egg in the ovary

LH (luteinising hormone)PituitaryStimulates release of the egg (ovulation)

OestrogenOvaryInvolved in maintaining the uterus lining

ProgesteroneOvaryInvolved in maintaining the uterus lining

Memory Hook

Two glands, two hormones each. Pituitary releases the two "stimulating" hormones (FSH and LH). The ovary releases the two "lining" hormones (oestrogen and progesterone).

The 28-Day Cycle — Four Stages

A typical cycle is ~28 days. Four phases, each dominated by different hormones.

Quick Mapping

Days 1–4: lining sheds. Days 5–14: FSH + oestrogen dominate, lining rebuilds. Day 14: LH surge → ovulation. Days 15–28: progesterone maintains lining; if no pregnancy, all hormones fall and cycle restarts.

HT — Follicular Phase & Ovulation

HT only. The first half of the cycle (days 1–14) is a chain of four hormone interactions ending in ovulation.

HT Spec Outcome

HT onlyExplain the interactions of FSH, oestrogen, LH and progesterone in the control of the menstrual cycle.

Step 1

FSH (from the pituitary) stimulates an egg follicle in the ovary to mature.

Step 2

The maturing follicle produces oestrogen (from the ovary), which builds up the uterus lining.

Step 3

Rising oestrogen inhibits FSH (negative feedback — only one follicle matures) and stimulates LH production.

Step 4 — Ovulation

LH (from the pituitary) surges and triggers ovulation — the egg is released from the ovary, around day 14.

HT — Luteal Phase (Days 15–28)

HT only. After ovulation, a fourth hormone takes over. The cycle pauses, waiting to see if fertilisation has occurred.

After Ovulation

The empty follicle becomes the corpus luteum, which now releases progesterone.

Progesterone's Two Jobs

1. Maintains the uterus lining — ready for a fertilised egg to implant.

2. Inhibits FSH and LH — no new follicle develops, no second LH surge.

Mark Scheme Phrasing

For HT mark schemes, write: "Progesterone (released from the corpus luteum / ovary) inhibits FSH and LH production, and maintains the uterus lining ." Two named effects = two marks.

HT — Cycle Restart or Pregnancy

HT only. What happens at the end of the luteal phase depends on whether the egg was fertilised.

No Fertilisation

Corpus luteum breaks down.

Progesterone falls.

Uterus lining is no longer maintained — it sheds (menstruation).

Inhibition of FSH lifts → FSH rises → new cycle begins.

If Fertilised

Fertilised egg implants in the lining.

Corpus luteum (then placenta) keeps producing progesterone.

Uterus lining maintained throughout pregnancy.

FSH and LH remain inhibited — no new cycles during pregnancy.

Why It Matters

Hormonal contraceptives exploit this feedback loop directly — they keep progesterone (and sometimes oestrogen) artificially high, which keeps FSH suppressed. No FSH → no maturing follicle → no ovulation.

HT — Reading Hormone Graphs

HT only. Hormone graph questions are the highest-mark format on this topic. Examiners want the right direction of cause.

Skill — HT

HT onlyExtract and interpret data from graphs showing hormone levels during the menstrual cycle (spec MS 2c).

Three-Step Method

Read the question stem. It tells you which is cause and which is effect.

Identify the correlation direction. "As X rises, Y rises" — state X first if the question asks what causes Y.

Quote specific values from the graph (e.g. "between days 5 and 12"). Vague answers like "oestrogen rises" lose data marks.

Common Trap

If the question asks for evidence that follicles release oestrogen, you must say: "as follicle volume rises, oestrogen concentration rises". Mark schemes do not accept the reverse causation ("oestrogen causes follicle volume to rise"). Same data, wrong direction.

The Seven Named Contraception Methods

The spec lists exactly seven methods. Memorise all seven by category. Mark schemes credit named methods only.

TypeMethodHow it works

HormonalOral contraceptives (the pill)Contain hormones to inhibit FSH production — no eggs mature

Injection / implant / patchSlow-release progesterone — inhibits maturation and release of eggs for months/years

BarrierCondoms / diaphragmsPrevent sperm reaching the egg

IUDIntrauterine devicesPrevent implantation of an embryo OR release a hormone

ChemicalSpermicidal agentsKill or disable sperm

BehaviouralAbstinenceNo intercourse when an egg may be in the oviduct

SurgicalMale / female sterilisationVasectomy or tubal ligation — permanent

How Hormonal Contraception Actually Works

The mechanism is the highest-yield mark scheme point on the topic. The pill doesn't kill sperm; it stops eggs maturing.

Mechanism

Oral contraceptives contain oestrogen and/or progesterone → these hormones inhibit FSH production by the pituitary → no egg matures in the ovary → no ovulation → fertilisation cannot occur.

Slow-Release Methods

Injection, implant, and skin patch contraceptives use slow-release progesterone — the spec describes their action as "inhibiting the maturation and release of eggs" for a number of months or years. (Biologically, this works via the same FSH/LH suppression — but use the spec's exact wording for the mark.)

Exam Phrasing

Write the full chain: "hormones inhibit FSH → no egg matures → no ovulation → no pregnancy." Each link in this chain is a separate mark scheme point.

Evaluating Contraception Methods

The spec asks you to evaluate — meaning weigh pros and cons. Three dimensions matter: effectiveness, STI protection, reversibility.

MethodEffectivenessSTI protectionReversible?

Hormonal (pill, implant)Very highNoYes

Barrier (condom)Lower than hormonalYes (condoms only)Yes

IUDVery highNoYes

SterilisationVery high (permanent)NoNo

Spec Note — WS 1.3

AQA also tests "why issues around contraception cannot be answered by science alone" — religious, ethical, cultural, and personal factors all influence the decision. Mention these in extended-evaluation questions.

Examiner Alert — Source & Direction

The two highest-impact warnings on this topic. Both are flagged in recurring examiner reports.

Source Confusion

FSH and LH come from the PITUITARY.Oestrogen and progesterone come from the OVARY (specifically the corpus luteum for progesterone). Examiner reports note students frequently swap these. Mark schemes credit the named source only.

Direction of Cause

If a question asks what causes a downstream effect (e.g. uterus lining thickening), the chain is FSH → oestrogen → effect. Examiners flag answers that suggest a "direct link" between FSH and the effect, skipping oestrogen. Don't compress the chain.

✗ Loses Marks

"FSH thickens the uterus lining."Skips the oestrogen step.

✓ Gets Marks

"FSH stimulates the follicle to release oestrogen, which thickens the uterus lining."Full chain — two marks.

Worked Example — PEE Framework

A 3-mark AO1 question on the most-tested mechanism in this topic.

Q: Explain how oral contraceptives prevent pregnancy. 3 marks

P

Point. Oral contraceptives contain hormones (oestrogen and/or progesterone) that inhibit the production of FSH by the pituitary.

E

Evidence. Without FSH, no egg matures in the ovary.

E

Explain. If no egg is released (no ovulation), fertilisation cannot occur — so pregnancy is prevented.

Why this scores 3/3

One mark per link in the chain: hormones inhibit FSH ✓ · no egg matures ✓ · no ovulation → no fertilisation ✓. The "so that…" linker at the end is what turns Describe into Explain.

Your Turn

FSH, LH, oestrogen and progesterone

For each hormone, state the gland that produces it and describe its main role in the cycle. 4 marks

Plan four marking points before revealing the solution — one for each hormone (both source AND role needed for the mark).

1

FSH: produced by the pituitary; causes the maturation of an egg in the ovary.

2

LH: produced by the pituitary; stimulates the release of the egg (ovulation).

3

Oestrogen: produced by the ovary; involved in maintaining the uterus lining.

4

Progesterone: produced by the ovary; maintains the uterus lining.

Mark-scheme matches: FSH source + role ✓ · LH source + role ✓ · oestrogen source + role ✓ · progesterone source + role ✓. 4 / 4.

HT extension would credit the additional interactions: oestrogen inhibits FSH and stimulates LH; progesterone inhibits FSH and LH.

Common Errors to Avoid

Four mistakes mark schemes penalise every year on this topic.

✗ Wrong

"FSH releases the egg."

✓ Right

FSH matures the egg; LH releases the egg (ovulation).

✗ Wrong

"Oestrogen comes from the pituitary."

✓ Right

Oestrogen comes from the ovary ; FSH and LH come from the pituitary .

✗ Wrong

"Condoms prevent ovulation."

✓ Right

Condoms are barrier — they prevent sperm reaching the egg. Ovulation still happens.

✗ Wrong

"Hormonal contraceptives protect against STIs."

✓ Right

Only barrier methods (condoms) protect against STIs. Hormonal methods do not.

Summary — Three Takeaways

1. Two Glands, Four Hormones

Pituitary : FSH (matures egg) and LH (releases egg).

Ovary : oestrogen (builds and maintains lining) and progesterone (maintains lining).

Testosterone (male, from testes) stimulates sperm production.

2. The Feedback Loop HT only

FSH → maturing follicle → oestrogen → builds lining → inhibits FSH , stimulates LH .

LH surge → ovulation → corpus luteum → progesterone → maintains lining → inhibits FSH and LH.

No fertilisation → progesterone falls → lining sheds → new cycle.

3. Contraception — Seven Methods, Three Trade-offs

Mechanism families : hormonal (inhibit FSH) · barrier (block sperm) · IUD · spermicide · abstinence · surgical.

Trade-offs : effectiveness vs STI protection vs reversibility. Only condoms protect against STIs. Only sterilisation is (effectively) permanent.

Next Lesson

Lesson 5.08 (HT only) — Using hormones to treat infertility: fertility drugs (FSH and LH injections) and IVF.