Why do submerged plants receive weaker illumination than exposed floating plants in a lake ?

In most animals, the metabolic reactions proceed in a …$A$… temperature range (in humans, it is $37^{\circ} C$ ). But there are microbes (archaebacteria) that flourish in hot springs and deep sea hydrothermal vents where temperature far exceed …$B$…

Choose the correct option for $A$ and $B$

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 ?

Species that can tolerate narrow range of temperature are called $………….$ .

Genetically adapted population to a particular habitat is called