Question

Metameric Segmentation is the characteristic of
A. Platyhelminthes and arthropoda
B. Echinodermata and annelida
C. Annelida and arthropoda
D. Mollusca and chordata

Answer 1

Hint: Segmentation: These types of animals are those who are considered to have organs that were repeated or to have a body composed of self-similar units.
It is the part of an organism which is known as being segmented.
Segmented animals are Annelida, Arthropoda, and Chordata.

Complete answer:
In order to solve this question we need to learn more about metamerism.
> Metamerism: It is a condition in which an organism forms a continuous series of body segments.
For example, metamerism is exhibited by earthworms.
The body is divided into segments which are also known as metameres.

> Metamerism segmentation: The repetition of organs and tissues at intervals along the body of an animal, which divides the body into a linear series of similar parts or segments (metameres).
It is most commonly seen in phylum Annelida and phylum Arthropoda.

> Platyhelminthes: these types of organisms are flatworms that lack a coelom and are parasitic in nature.
It lacks either a circulatory or respiratory system.

> Echinodermata: Echinodermata is a marine animal.
It has a star shaped appearance.
These organisms are trophoblastic in nature.

> Mollusca: Mollusca are the largest phylum of invertebrate after the phylum arthropoda.
But the rate of segmentation is not seen in the molluscas.

> Chordata: chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail.
These features define the phylum chordata.

> Annelida and Arthropoda are the only phylum which shows the metamerism segmentation feature.
Annelida are leech, earthworms, Lugworms.
Arthropoda are Spiders, scorpions, Horseshoe crabs.

So, the correct option is option c. Annelida and Arthropoda.

Note:
> Characteristics of arthropoda are:
- Exoskeleton is made up of chitin
- Having segmented body
- Bilateral symmetry
- Highly developed sense organs.

> Characteristics of Annelida are:
- Bilateral symmetry
- Coelom is present
- Parapodia is present
- Segmented body