S3 Science: Human Reproduction And Puberty (Paper 1 (basics))

S3 Science: Human Reproduction and Puberty (Paper 1 (basics))

2026-11-14

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Tutor Prep Guide · the male and female reproductive systems, sperm and eggs, fertilisation and implantation, the menstrual cycle, puberty and sex hormones, pregnancy and fetal development, the placenta and umbilical cord, twins, contraception and sexually transmitted infections

S3 Science: Human Reproduction and Puberty (Paper 1 (basics))

This paper starts from the basic functions of the reproductive organs and practises the division of work between testes and ovaries, the site of fertilisation, chromosome numbers in gametes and the zygote, the days of a 28 day cycle, weeks converted to days, with simple work on age span and total ovulations.

Direct answers　The testes make sperm and release testosterone; the ovaries make eggs and release oestrogen; fertilisation happens in the oviduct; gametes have 23 chromosomes and the zygote 46; ovulation is around day 14 of a 28 day cycle; 40 weeks is 280 days; the span from age 9 to 14 is 5 years; a 5 day period leaves 23 non-menstrual days; 40 years at 12 ovulations a year gives 480; the placenta exchanges materials without mixing blood.

01　Paper details (check answers afterwards)

Item	Detail
Questions	10
Suggested time	20
Difficulty mix	Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1
Chapter	Chapter: S3 Science: Human Reproduction and Puberty
Level	S3

02　Questions (10 items)

FoundationWhich organ makes sperm in the male body?
FoundationWhich organ makes eggs in the female body?
FoundationWhere does fertilisation normally take place?
IntermediateSperm and egg each carry 23 chromosomes. How many does the zygote have?
IntermediateIn a 28 day cycle with ovulation around day 14, how many days pass from the first day of menstruation to ovulation?
IntermediateA pregnancy lasts about 40 weeks. How many days is that at 7 days per week?
ChallengeFemale puberty runs roughly from age 9 to 14. What is that age span in years?
ChallengeIn a 28 day cycle with 5 days of menstruation, how many non-menstrual days are there?
ChallengeA woman ovulates from age 12 to 52, that is 40 years, at 12 times a year. How many ovulations in total?
Error redoCommon error: the blood of the fetus mixes directly with the blood of the mother. What is correct?

03　Answers and one-line notes

#	Answer	One-line note
1	The testes, one on each side	The seminiferous tubules inside the testes make sperm and also release testosterone.
2	The ovaries, one on each side	The ovaries also release oestrogen and, after puberty, usually release one egg each month.
3	In the oviduct	Sperm meets the egg in the oviduct to form a zygote, which then travels to the uterus.
4	46 chromosomes, or 23 pairs	23 plus 23 gives 46, one set from the father and one from the mother.
5	14 days	The first half of the cycle is about 14 days and the time from ovulation to the next period is also about 14 days.
6	280 days	40 times 7 gives 280, and the due date is estimated from a 280 day pregnancy.
7	5 years	14 minus 9 gives 5, though the actual starting age varies a lot between individuals.
8	23 days	28 minus 5 gives 23, but non-menstrual days are not all safe days.
9	480 times	40 times 12 gives 480, though pregnancy, breastfeeding and irregular cycles reduce the real number.
10	The two bloods never mix; nutrients and oxygen are exchanged across the placenta	The placenta is the exchange surface and the mother and the fetus each keep their own circulation.

04　What to do after marking

After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
Repeat the same item two days later; move to the next paper only when both attempts are correct.
Parents only need the answer and note columns; there is no need to explain every item.

Sort reproduction questions by place and order first: the testes make sperm, the ovaries make eggs, fertilisation happens in the oviduct and implantation in the uterus, while the placenta and umbilical cord carry nutrients and oxygen; for cycle questions draw the days on one timeline and remember the fertile window runs about three days before and one day after ovulation.Tutor Registration →

Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.