$A$: Some organisms can maintain internal homeostasis by means of physiological processes and are called 'Regulators'.
$R$: 'Regulators' can maintain internal homeostasis only up to a limit of stressful conditions.

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

Consider the following four statements regarding certain desert animals like the kangaroo rat:
$(a)$ They have a dark color,a high rate of reproduction,and excrete solid urine.
$(b)$ They do not drink water,breathe slowly to conserve water,and their body is covered by thick hair.
$(c)$ They use dry seeds as food and do not require drinking water.
$(d)$ They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements are true for such animals?

Identify the organism based on the following characteristics:
- It has the ability to concentrate its urine.
- It meets its water requirements from internal fat oxidation.
- It is found in the American desert.

Changes in the body form of some planktonic animals with seasonal changes in temperature are grouped under

Define/Explain: Ecological niche.