Question

Sea Anemone has a symmetry
A. Bilateral
B. Spherical
C. Pentamerous
D. Radial/Biradial

Answer 1

Hint: Sea anemones are the aquatic, predatory mammals of the group Actiniaria. They are termed after the anemone, a temporal flowering plant, because of the colourful features of many. Sea anemones are arranged in the class Anthozoa, phylum Cnidaria, subclass Hexacorallia.

Complete Answer:
Let us analyze the correct answer,
Option A: Bilateral symmetry can be defined as a type of symmetry in which both the sides are similar, i.e. the right and left side in a sagittal plane are the same. It is generally seen in animals of higher order like humans, cats, etc. Therefore, this is the incorrect option.

Option B: Spherical symmetry is defined by the capacity to draw an infinite, or great but limited, number of symmetry axes through the body. This indicates that spherical symmetry happens in an organism if it can be cut into two twin halves through any cut that runs by the organism's centre. Therefore this is the incorrect option.

Option C: Pentaradial symmetry ('Penta-' denotes five) reflects a model where the organs of the animal section out into five separate chambers or arms. Pentaradial symmetry is also identified as pentamerism, another term mentioned to the number five. It is generally seen in starfish. This is the incorrect option.

Option D: Radial symmetry can be defined as a kind of symmetry about a central axis. It is generally seen in animals which have top and bottom surfaces but they do not have right and left sides. Therefore, this is the correct option. The side with a mouth is known as the oral side and the side without a mouth is known as the aboral side.

Thus, option D) Radial/ biradial is the correct answer.

Note: One of the basis to classify animals is on the basis of symmetry. There are two types of symmetry,
1. Radial symmetry - In this, any plane passing through the central axis divides the body of the animal in two equal halves and the examples include echinoderms, ctenophores, etc
2. Bilateral symmetry - in this, a single plane divides the body into two equal halves and examples include annelids, arthropods, etc.