Question

Why is it , that asexual reproduction produces exact copies , but sometimes minor variations are also sees in next progeny ?

Answer 1

In asexual reproduction, only one parent is involved in the reproduction process. So the off spring gets the same features as the parent. These are the clones that are exact copies o the parent

While the off spring that are different from parents is due to mutation. These sudden errors that occur during reproduction causes the variation in off spring.