Question

Radial symmetry occurs in
A) Cockroach
B) Anopheles
C) Asterias starfish
D) Snail

Answer 1

Hint: Radial symmetry is defined as the symmetry, which makes two identical body parts from the central axis. If radial symmetry presents in any organisms and we cut those organisms from the centre, two halves are formed which are identical.

Complete Answer:
1) Cockroach, anopheles, and snails have bilateral symmetry.
2) Only a very small group of species show radial symmetry like some marine animals and sponges.
3) Asterias starfish have the star like body structure which comes under the star like echinoderms.
4) These echinoderms belong to the class of Asteroidea that is why starfish are also named as Asteroids.
5) Starfish having the five arms like a star and a central disc. The above surface is smooth, granular or spiny and enclosed with plates.
6) They have the ability to regenerate the damaged or lose arms.

So, the correct answer is Asterias starfish have the radial symmetry.

Additional information:
(I) The maximum life span recorded of starfish is 34 years.
(II) Starfish make their internal electrolyte balance according to the sea water, so for them survival in fresh water is not possible.
(III) Echinoderm is called because they fall under the phylum of Echinodermata.

Note: Majorly of starfish have five arms from the central disc but these vary from species to species, some of them having six to seven arms or another having 15-18 arms.