Which branch of biology is related to the study of fossils?

According to our convention,when do we focus on the defining characteristics of a living organism?

Biologists focus on which aspect to identify a living organism?

Select the correct option from the following:

Assertion: The number of cells in a multicellular organism is inversely proportional to the size of the body.
Reason: All cells of the biological world are alive.

Which of the following statements is not related to taxonomy?