Receptors for sperm binding in mammals are present on:

Meiotic division of the secondary oocyte is completed:

1. At the time of copulation

2. After zygote formation

3. At the time of fusion of a sperm with an ovum

4. Prior to ovulation

Extrusion of the second polar body from the egg nucleus occurs:

1. simultaneously with the first cleavage

2. after entry of sperm but before fertilization

3. after fertilization

4. before entry of sperm into the ovum