Which one of the following correctly represents an organism and its ecological niche?

Ecological equivalents refer to:

Which rule states that mammals living in colder climates generally have shorter ears and limbs to minimize heat loss?

The region consisting of long and severe winters and a growing season consisting of a few months of summers constitutes:

Populations of different species living together in a common habitat form which of the following?

Consider the following four conditions $(i-iv)$ and select the pair that represents the adaptation of desert lizards to their environment.
$(i)$ Burrowing into the soil to escape high temperatures.
$(ii)$ Rapidly losing body heat during high temperatures.
$(iii)$ Basking in the sun and absorbing heat when the temperature is low.
$(iv)$ Insulating the body due to a thick layer of fat.