The only human system that is derived from all the three germ layers is
Digestive system
Excretory system
Respiratory system
Nervous system
Assertion : Senescence is the time when age associated defects are manifested.
Reason : Certain genes may be undergoing sequential switching on and off during one's life.
Fructose is present in the secretion of
Ejaculation is the $...A...$ response. Erection is a $...B...$ response. Here, $A$ and $B$ refers to
In Pheretima mouth develops from which of the following
Spermiogenesis or spermatiliosis is