Question

To which phylum does earthworm belong?
A. Platyhelminthes
B. Aschelminthes
C. Annelida
D. Arthropoda

Answer 1

Hint: An earthworm is a segmented worm. They are terrestrial invertebrates and feed on organic matter. They are also called farmer’s friends because they help to increase the fertility of the soil.

Complete answer:
Earthworms belong to the phylum Annelida. They possess a segmented tube-shaped body that is reddish-brown. Their body is divided into small segments. The dorsal side holds the dark line of blood vessels whereas the ventral side comprises of genital openings. The earthworm can carry both males as well as female sex organs. It has four pairs of spermathecal apertures that are accommodated in the segments 5-9. The body of an earthworm is externally covered by a thin layer of non-cellular cuticle two muscle layers, and the inner layer is sheathed above, which lies a layer of the epidermis and on the top lies a layer of the epidermis and the cuticle. Earthworms are said to be monoecious or hermaphrodite in that both males and female reproductive organs are present in one individual but self-fertilization does not occur and the female does not mature at the same time. They show a bilateral symmetry organ system body organisation.
Thus, the correct answer is option C.

Note: In annelids, nephridia help to carry out osmoregulation and excretion. Humus is a dark-coloured amorphous substance that is highly resistant to microbial activities. Thus, it undergoes decomposition at an extremely slow rate. Due to it being collided in nature, it has many nutrients dissolved in it. Humus is further broken down by microorganisms to release inorganic nutrients. This is known as mineralization.