Q.Fill in the blank.
The time period from birth to the natural death of an organism is known as _______.

Every organism's life passes through three distinct phases. The juvenile phase (or vegetative phase) is the span of pure growth between birth and reproductive maturity. During the reproductive phase (maturity phase) that follows, the organism actually reproduces, and its offspring in turn grow toward their own maturity. Once the reproductive phase ends, the organism enters the senescent phase, when degenerative changes set into the structure and functioning of its body. Organisms also differ in exactly when, within their reproductive phase, they breed: seasonal breeders reproduce only during a particular period of the year …