Which centriole of spermatozoa is required for first cleavage?

Which of the following is similar in function to Cowper's gland

Vegetal hemisphere of egg consists of

Archenteron is lined with

Which of the following is not evident that the pattern of cleavage is determined by factors in the egg cytoplasm rather than by genes of zygote

Which one of the following is the most widely accepted method of contraception in India, at present?