State whether the following statements are True or False. If false, correct the statement:
(a) External fertilization can occur both in water and on land.
(b) The eggs of fish are covered by hard shells for protection.
(c) The human egg has a head, middle piece, and tail.
(d) In adult human females, a single mature egg is released into an oviduct every month.
(a) False.
External fertilization occurs only in water and not on land because of lack of protective environment to the gametes, and lack of means of transfer of gametes on land. In water, the gametes are well protected and easily transferable.
(b) False.
The fishes exhibit external fertilization. The eggs layer are unfertilized and covered only by a slimy, jelly-like substance for protection. No hard shell is present.
(c) False.
Human egg is a single round cell, without any distinctive parts. Head, middle piece and tail are present in human sperm, which is the male gamete.
(d) True.
In humans, the ovaries alternatively release one mature egg cell every month into the oviducts or fallopian tubes.