Question

The mechanism of fertilization involves different events like approximation of gametes, acrosomal reaction activation of egg and amphimixis. According to F.R. Lillie approximation occurs due to interacting complementary substances called as fertilizin and anti fertilizin.
During amphimixis many events occur. Choose the incorrect event from the following events.

• A. Swelling of the sperm nucleus
• B. Initial movement of the male pronucleus along the copulationpath
• C. Establishment of achromatic spindle by the proximal centriole
• D. Completion of second meiotic division if it has not occurred already

Answer 1

The correct option is B Initial movement of the male pronucleus along the copulationpath

F.R. Lillie proposed fertilization theory in 1914 which is based on Sea urchin. According to this theory, egg (ocum) secretes a chemical called fertilizin and sperm on its surface a protein called anti-fertilizin. The fertilizin of an egg interacts with the anti-fertilizin of the sperm of the same species. This interaction makes the sperms stick to the egg surface. The adhesion of sperm to the egg of the same species through chemical recognition is known as agglutination.

He showed that the sperm did not enter into the egg by simple mechanical boring. Instead, the presence of the sperm calls forth a reaction on the part of the egg that leads to the absorption of the former. Here, there is no copulation path where the male pronucleus will move on.
Thus, the correct answer is option (B).