Question
How can we say that fish exhibits external fertilisation?
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Answer
Female fish lay eggs in water while male fish releases its sperms in water. Sperms swim and reach the eggs of fish, randomly due to water currents. When a sperm comes in contact with the viable egg, nuclei of both the cell fuses to form a zygote. This process of fertilisation takes place in water outside the female body, hence fertilisation is external in fishes.
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