Reproductive System — Part 2: From fertilisation to birth: visual lesson, ICSE Class 10 Biology (Science Paper 3)

Lesson

From Fertilisation to Birth

Part 2 — how a new life begins, grows and is born, the monthly cycle, and twins.

In this lesson you will

Define fertilisation, implantation, gestation and parturition and put them in order
Explain the functions of the placenta, the amnion and the amniotic fluid
Outline the menstrual cycle and the roles of the sex hormones, and distinguish identical from fraternal twins

Concept

Table of events from fertilisation to birth, what happens and where
Event	What happens	Where
Fertilisation	Nuclei of a sperm and an egg fuse to form a diploid zygote	Oviduct
Cleavage	The zygote divides repeatedly as it moves down	Oviduct
Implantation	The young embryo sinks into the thick uterine lining, about a week after fertilisation	Uterus
Gestation	The embryo, later called a foetus, develops	Uterus
Parturition	Uterine contractions push the baby out	Uterus, cervix, vagina

Check your understanding

Fertilisation normally takes place in the…

Multiple choice1 mark

In humans, fertilisation normally takes place in the