Succulent plants are fleshy xerophytes, which can grow in low water level area (desert). That is why, they are called as desert plants.

Correct Option: B

Succulent plants are fleshy xerophytes, which can grow in low water level area (desert). That is why, they are called as desert plants.

The correctly matched pair is streamlined body for aquatic adaptation. Parasitism-inter specific relationship in which one species (parasite) benefits for growth and reproduction and other species (host) harmed. Parasite live on or inside the body of host.

Correct Option: D

The correctly matched pair is streamlined body for aquatic adaptation. Parasitism-inter specific relationship in which one species (parasite) benefits for growth and reproduction and other species (host) harmed. Parasite live on or inside the body of host.

This is one of the reasons for organisms being homeostatic (constant body temperature).

Correct Option: B

This is one of the reasons for organisms being homeostatic (constant body temperature).

The keystone species in an ecosystem are those who are the main contributors to the ecosystem.

Correct Option: D

The keystone species in an ecosystem are those who are the main contributors to the ecosystem.

Two or more species which are reproductively isolated from each other but are morphologically quite similar are known as sibling species. Sympatric species are developed due to reproductive isolation and occur in overlapping or same area of geographical distribution. Parapatric species are developed in adjacent geographical areas meeting in very narrow regions of overlap.

Correct Option: C

Two or more species which are reproductively isolated from each other but are morphologically quite similar are known as sibling species. Sympatric species are developed due to reproductive isolation and occur in overlapping or same area of geographical distribution. Parapatric species are developed in adjacent geographical areas meeting in very narrow regions of overlap.