. Differentiate between the folowing
(a) Semen and sperm
(b) Implantation and pregnancy
(c) Follicle and corpus luteum
(d) Amnion and allantois
(e) Prostate gland and Cowper's gland (the nature of secretion)
(f) Identical twins and fraternal twins
(a) Sperm is the male gamete produced by the testes. Semen on the other hand is the mixture of sperms and alkaline secretions from the seminal vesicle, prostate gland and Cowper's gland.
(b) Implantation is the fixing of embryo in the wall of uterus. The state that implantation produces is known as pregnancy.
(c) Follicle is the cellular sac containing a maturing egg. Corpus luteum on the other hand is the remnant of the follicle the release of ovum during ovulation.
(d) Amnion is a sac which develops around the embryo whereas allantois is an extension from the embryo which forms villi of placenta.
(e) Sterility is the incapability to produce sperms whereas impotency is the inability to copulate.
(f) Prostate gland pours alkaline secretions into the semen to neutralize the acid in female's vagina whereas the secretion of Cowper's gland serves as a lubricant.
(g) Identical twins are produced from one ovum i.e. one developing zygote splits and grows into two foetuses whereas fraternal twins are produced when two ova get fertilized at a time.