Nearly all plants and an overwhelming majority ($99\;\%$) of animals are categorised as

$A$… regulators are able to maintain homeostasis by means which ensures constant body temperature, constant osmotic concentration, etc. All …$B$… and …$C$…. and is very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation)

Evolutionary biologists believe that the 'success' of mammals is largely due to their ability to maintain a constant body …$D$… and thrive whether they live in Antarctica or in the Sahara desert
Choose the correct option for $A , B , C$ and $D$

Body compensates low oxygen availability at high altitudes by

$I.$ increasing $RBC$

$II.$ decreasing binding affinity of haemoglobin

$III.$ increasing binding affinity of haemoglobin

$IV.$ increasing breathing rate

$V.$ decreasing breathing rate

Choose the correct option for given statement

– It has the ability to concentrate its urine.

– It provide water requirements from its internal fat oxidation.

– It is present in American desert.

Give differences : Ectotherms and Endotherms