Which scientist proposed that a population is a group of individuals of the same species?

How many of the following statements are correct about niche?
$i$. It denotes the functional role played by an organism.
$ii$. It deals with the flow of energy from one organism to another.
$iii$. As soon as a niche is left vacant,other organisms fill that position.
$iv$. The same niche is shared by two or more species.
$v$. Organisms living in the same habitat differ in their niches.

Which of the following is a characteristic of a biological community?

In a sea shore,the benthic animals live in sandy,muddy and rocky substrata and accordingly developed the following adaptations:
$(a)$ Burrowing
$(b)$ Building tubes
$(c)$ Holdfasts / peduncle
Match the suitable substratum against each adaptation.

Match the following types of adaptations in Column-$I$ and Column-$II$.

Column-$I$	Column-$II$
$i$. Morphological	$a$. Crassulacean Acid Metabolism
$ii$. Physiological	$b$. Migration of birds
$iii$. Behavioural	$c$. Leaves reduced to spines in Opuntia

Alpine tundra is found in