Reproductive System and Development
Gametes fuse in fertilisation and the embryo develops.
About this topic
In humans, males produce sperm in the testes and females produce eggs in the ovaries, controlled by hormones (testosterone, oestrogen, progesterone). In fertilisation a sperm fuses with an egg, forming a zygote that divides into an embryo and implants in the uterus lining.
The embryo develops through the foetal stages, nourished via the placenta and umbilical cord, over about nine months. Development involves cell division, differentiation and growth. Birth is triggered by hormones, and breast milk then supplies nutrition and antibodies.
After ovulation around day 14, the egg travels down the oviduct, and if sperm are present, fertilisation occurs there. The zygote divides repeatedly into a ball of cells, which implants in the uterus lining about a week later. The placenta lets oxygen and nutrients pass from mother to fetus and waste pass back, without mixing their blood. Pregnancy lasts about 40 weeks.
The menstrual cycle is controlled by FSH, LH, oestrogen and progesterone with feedback between them. Contraception methods include condoms, which also protect against infections, and hormonal pills. Puberty is triggered by rising sex hormones. Students often think the egg is released each time at the end of the period; ovulation occurs mid-cycle, and menstruation is the shedding of the uterine lining.
Key ideas
- Sperm and egg
- Zygote divides
- Placenta nourishes the fetus
Quick check
Use cases: where Reproductive System and Development helps
- Homework: review the key idea behind Reproductive System and Development before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Reproductive System and Development without notes.
- Visual learning: play with the interactive lab to see how Reproductive System and Development changes when you adjust its inputs.
- Teaching a friend: explain Reproductive System and Development in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Reproductive System and Development?
Gametes fuse in fertilisation and the embryo develops.
What will I learn in Reproductive System and Development?
Sperm and egg. Zygote divides. Placenta nourishes the fetus.
Is Reproductive System and Development part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Reproductive System and Development lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Reproductive System and Development?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.