Difference between amphigamy and amphimixis

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Please find below the answer:

In sexual reproduction, both male and female gametes (i.e. sperm and egg) are fused to form a zygote. This is known as amphimixis.
Amphigamy also refers to the same phenomenon. It is normal cross-fertilization or fusion or male and female gametes. 

Note: In botany, the term 'amphigamous' is used to describe an entirely cellular structure with no distinction of sexual organs.

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