Tag: earthworm

Leech belongs to phylum Annelida. The 'green spoonworm' (Bonellia viridis) lives in a marine habitat. It shows sexual dimorphism. It is also known as the biocidal properties of a pigment in its skin. It is found in the north-eastern Atlantic, Indian and Pacific Oceans and the Mediterranean and Red seas. It is pale- to dark-green in colour, with a 15 cm long, round or sausage-shaped body. Hence, option B is correct.

Earthworms are hermaphrodites; that is, they have both male and female sexual organs.  The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts are in segment 13 release eggs. Ovarian funnels are present beneath the ovaries which continue into the oviduct, join together.

The spermathacae are also called as receptaculum seminis. species of earthworms have four pairs of spermathecae one pair each in the 6th, 7th, 8th, and 9th segments. The spermathecae receive and store the spermatozoa of another earthworm during copulation. They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes.

Two pairs of accessory glands are present in 17th and 19th segments. Four pairs of spermathecae are located in 6th-9th segments. They receive and store spermatozoa during copulation. One pair of ovaries is attached at the inter-segmental septum of the 12th and 13th segments.

Tapeworm and fluke worms belong to class Platyhelminthes. They both are having well developed reproductive systems.

Earthworms are hermaphrodite animals, meaning that both testes and ovary are present in a single body but cross-fertilisation is the rule. At the time of reproduction two worms come to lie close to each other and exchange sperms. The sperms are stored in pouches called spermatheca. So, the correct answer is option C.

Respiration takes place through the moist surface of the body of an earthworm. Moist surface aids in easy diffusion of gases. Haemoglobin is the respiratory pigment that helps in transportation of oxygen to different parts of the body.