The physical space occupied by the organism is called its . . . . . . niche.

Species which occupy a similar ecological niche in similar communities occupying different biogeographical regions are called:

In the given graph,what does the horizontal line passing through the middle represent?

In desert grasslands,which type of animals are relatively more abundant?

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

Consider the following four statements $(1-4)$ about certain desert animals such as kangaroo rat.
$(1)$ They have dark colour and high rate of reproduction and excrete solid urine.
$(2)$ They do not drink water,breathe at a slow rate to conserve water and have their body covered with thick hairs.
$(3)$ They feed on dry seeds and do not require drinking water.
$(4)$ They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements for such animals are true?