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Assertion: All copulations do not lead t...

Assertion: All copulations do not lead to the fertilisation and pregnancy.
Reason: Fertilisation can occur only if the ovum and sperms are transported simultaneously to the ampullary isthmic junction.

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The correct Answer is:
A
Fertilisation can only occur if the ovum and sperms are tranported simultaneously to the ampullary-isthmic junction and ovum is released only once a month. This is one of the reasons why all copulations do not lead to fertilisation and pregnancy.
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