In lower organisms,the formation of thick-walled spores helps them to survive in unfavorable conditions. What is this process called?

The biosphere is composed of ......

Read the following statements and select the option that represents the correct statements.
$(1)$ Kangaroo rats never drink water.
$(2)$ Birds undergo hibernation to escape adverse environmental conditions.
$(3)$ Thermal adaptation can be explained by Allen's Rule.
$(4)$ Opuntia possesses phylloclade for protection.

Some animals can change their body temperature according to the ambient temperature,then they are simply . . . . . . .

How many of the following pairs are correct regarding the thermal tolerance of organisms?
$(1)$ Aves - eurythermal
$(2)$ Mammals - stenothermal
$(3)$ Amphibia - stenothermal
$(4)$ Reptile - eurythermal

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