The distance between stars is measured in . . . . . . .

Which of the following pairs represents the defining features of living organisms?

Living organisms show responses to external factors like:

Non-living objects:
$(1)$ Grow from the external surface by collecting substances on it.
$(2)$ Grow from the internal surface like living organisms.
$(3)$ Do not grow at all.
Which of the following options is correct?

Which of the following organisms cannot reproduce?

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.