Assertion   :       Embryonic development proves interrelationship and common ancestory of metazoans.

Reason      :       It involves similar sequence of five dynamic processes during development.

Assertion   :       There is generally monospermy in most of animals.

Reason      :       Vitelline membrane of ovum checks polyspermy.

Assertion   :       Penetration of sperm into ovum is a chemical process.

Reason      :       Acrosome of sperm secretes a lytic enzyme hyaluronidase which dissolves vitelline membrane of ovum.

Assertion :     Cleavage is also called fractionating process.

Reason    :     In cleavage, number of blastomeres increases but size of blastomears decreases.

Assertion   :       Gastrular movements are morphogenetic.

Reason      :       During gastrulation, cells move in masses and towards definite direction.

Assertion   :       In human male, testes are extra-abdominal and lie in scrotal sacs.

Reason      :       Scrotum acts as thermoregulator and keeps testicular temperature lower by 2°C normal spermatogenesis.

Assertion   :       Urethra in human male acts as urinogenital canal.

Reason      :       Urethra carries only urine while sperms are carried by vasa deferentia only.

Assertion   :       At puberty, human male develops secondary sexual characters.

Reason      :       At puberty, there is decreased secretion of testosterone in male.

Assertion   :       Fallopian funnel of oviduct is with finger-like fimbriae.

Reason      :       Graafian follicle of ovary is with secondary oocyte hanging in cavity called antrum.

Assertion   :       Corpus luteum degenerates if the ovum remains unfertilized.

Reason      :       Corpus luteum secretes progesterone which maintains the pregnancy.