The sequence of steps in the history of an organism is called

Which one of the following plants does not show plasticity?

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.

The abscission layer is composed of .........

Suitable environmental conditions for seed germination are

Senescence in plants leads into . . . . . . of cells.