1. Ostrich has the largest eggs.
2. Amoeba and Hydra do not reproduce sexually because they do not have distinct male and female sexes. They do not produce sex cells or gametes. Hence, they reproduce asexually to grow and multiply or continue their life form.
3. In frogs, fertilisation takes place outside the body of the female. Female frogs lay eggs in large number because they are exposed to the external environment that may destroy many eggs. Hence, laying eggs in large number not only promotes fertilisation but also increases the chances of survival of at least few of the fertilised eggs.
4. No, the transformation of puppies into adult dogs is not called metamorphosis. Metamorphosis is the transformation of a larva into an adult. Dogs give birth to puppies, which grow into adults slowly.
5. If semen is not formed in male reproductive organs, then the male cannot fertilise the egg or ovum, as sperms will not reach the egg
6. Hermaphrodites are the organisms in which both the male and female sex organs are located. Earthworm and Hydra are the examples of hermaphrodites.
Full answer CLICK HERE
Basic science Class 8 chapter-conservation By Jsunil