How do plants produce seeds through apomixis ? Explain with the help of an example

Explain mutualism with the help of an example.

Explain commensalism, with the help of an example.

How do muscles work in pairs to move a bone? Explain with the help of an example.

What do you mean by restoring force? Explain with the help of an example.

How do organisms , whether reproduced asexually or sexually maintain a constant chromosome number through several generations ? Explain with the help of suitable example.

What do you mean by dimensions of a physical quantity? Explain with the help of an example.

(a) How is sound produced? Explain with the help of an example. (b) How does sound from a sound producing body travel through air to reach our ears? Illustrate your answer with the help of a labelled diagram.