NCERT Book Class 9 Science (Exploration) Chapter 11 Reproduction: How Life Continues

Chapter
Reproduction: How
11 Life Continues

Think It Over
You have learnt that one of the important characteristics of Grade 8
y When does a living beings is that they reproduce. Every organism has a Chapter
Curiosity
13
farmer prefer definite life span — it is born, grows, matures, reproduces
asexual or sexual and eventually dies. Reproduction is a biological process by which
methods of living beings produce new individuals of their own kind. This is how
reproduction for life on the Earth continues to exist. For example, a mango tree may
crops production?
grow old and die, but its seeds continue to grow as new mango plants.
y Why do you Similarly, cows give birth to calves, dogs to puppies, cats to kittens
think most and humans to children.
complex animals
and flowering You have also learnt that living beings reproduce in two main
plants use sexual ways — asexually, where a single parent produces offspring
reproduction, that are almost exact copies of the parent and sexually, where
while many simple offspring inherit a mix of characteristics from the two individuals.
organisms, like This mixing of characteristics may lead to the small differences
yeast and hydra between parents and their young ones. Accumulated over many
mainly reproduce generations, such differences help living beings adapt to changing
asexually?
environments, and sometimes even give rise to new kinds of