Sexual reproduction

The idea

Sexual reproduction needs two individuals, a male and a female, whose germ-cells join, by external release or by internal transfer, to create a new generation.

Calves and chicks

Bulls alone cannot produce new calves. Hens alone cannot produce new chicks.

What is needed for a new generation here?

• Both a male and a female
• Only the male
• Only the female

How germ-cells join

Open each tab.

A new generation from two

In sexual reproduction, germ-cells from the male and the female join. They can join outside the bodies, by external release, or inside, by internal transfer.

Sexual reproduction needs two individuals, a male and a female, whose germ-cells join, by external release or by internal transfer, to create a new generation.

Notes

Sexual reproduction needs two individuals, a male and a female. Their germ-cells join, by external release or internal transfer.

Check yourself

How many individuals does sexual reproduction need?

In flowering plants, how do the germ-cells come together according to the book?

Which cells join in sexual reproduction?

• Only one. A single individual creates a new generation in asexual reproduction.
• Two, a male and a female — correct. Yes!
• Three or more. Sexual reproduction needs two individuals, a male and a female.
• By two individuals joining their bodies for internal transfer. The book says internal transfer after joining bodies happens in many animals.
• They do not need to come together. In sexual reproduction germ-cells from two individuals have to join together.
• By external release from the bodies of individuals — correct. Yes!
• Germ-cells of the male and the female — correct. Yes!
• Two bud cells from one parent. Buds are formed in asexual reproduction from a single parent.
• Two spores from one parent. Spores are formed by one individual in asexual reproduction.