Reproduction is required for the perpetuation of
population. It is not necessary for the survival of living
organisms. Many organisms, e.g., mules, sterile worker
bees, infertile human couples are not able to reproduce,
while they have all other defining properties of life, so
they can be called as living.
Sexual reproduction involves the formation and fusion
of two kinds of gametes to produce an offspring. In
asexual reproduction, new individuals can arise by the
specialised parts of body or without the fusion of gametes.