IB Biology Sub-topic D3.1 Definitions

This page contains our IB Biology definitions for sub-topic D3.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Further reproduction'.
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external fertilization

The fusion of an egg and sperm outside the body, such as in fish and frogs

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fertilization

The fusion of an egg and sperm

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fetus

An embryo that has developed skeletal tissue by 8 weeks

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gamete

Sex cell

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internal fertilization

The fusion of an egg and sperm inside the body, such as in humans

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oogenesis

The production of female gametes in the ovaries, commencing in puberty and lasting until the eggs are run out

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polyspermy

The fertilization of an egg by more than one sperm, which increase chromosome number, usually resulting in cell death or birth to sterile offspring

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spermatogenesis

The production of male gametes in the testes, commencing during puberty and lasting indefinitely

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