Question

Deuterostomic body plan is a type of

• A. cell aggregate body plan
• B. tube-within-a-tube body plan
• C. blind-sac body plan
• D. protostomic body plan

Answer 1

The correct option is B tube-within-a-tube body plan

Deuterostomic body plan is a type of tube-within-a-tube body plan.
There are three different types of body plan:
a. Cell aggregate body plan: Body consists of an aggregate of the cells with almost no differentiation and are not organised into tissues or organs. Example: Sponges.
b. Blind-sac body plan: Body has a single cavity with one opening. Example: Hydra, Planaria.
c. Tube-within-a-tube body plan: Body of the animal consists of two tubes, one formed by the body wall and second formed within it by the digestive tract. Example: Ascaris.

Protostomic body plan and deuterostome body plan are the types of tube-within-a-tube body plan. In the deuterostome body plan, the anus of the digestive tract develops first in the embryo and mouth is formed later. Example: Starfish and higher animals such as birds, reptiles, etc. Protostomic body plan is a type of tube-within-a-tube plan where the mouth of the digestive tract develops first in the embryo and the anus is formed later Example: Roundworms, earthworms.