Select the correct option for the labeled part $X$ and $Y$ from the given diagram.

Define the following terms:
$(i)$ Poikilothermous
$(ii)$ Homoiothermous

Which of the following is wrongly matched?

Select the correct statement.

Match the animals listed in Column-$I$ with their respective zoological names given in Column-$II$; choose the answer which gives the correct combination of the alphabets of the two columns.

Column-$I$	Column-$II$
$(A)$ Starfish	$(p)$ Sepia
$(B)$ Jellyfish	$(q)$ Asterias
$(C)$ Devilfish	$(r)$ Aurelia
$(D)$ Cuttlefish	$(s)$ Octopus

Which of the following characteristics are $NOT$ common to both Aves (birds) and Mammalia (mammals)?
$I$ - Homeothermic (warm-blooded) animals.
$II$ - Respire through lungs.
$III$ - Possess a four-chambered heart.
$IV$ - Dioecious (sexes are separate).
$V$ - Possess hair on the skin.
$VI$ - Show internal fertilization.
$VII$ - Possess teeth.