Question

How does an earthworm fix parts of its body to the ground?
A. By muscle interaction and expansion
B. With the help of slimy substance secreted by its body
C. With the help of tiny bristles present under its body which project out
D. All the above

Answer 1

Earthworm is studied under the phylum Annelida of kingdom Animalia. Earthworms consist of approximately 100-150 segments. The segmented body provides earthworms important structural features.

Complete answer:
By muscle interaction and expansion -Earthworms do not have special organs of movement, but they are very active and quickly crawl .The movement process is actually the combined effect of contracting and relaxing the two muscle layers of the body wall, aided by deposits and the hydrostatic pressure created by the coelomic fluid. So this option is not correct.
With the help of slimy substance secreted by its body-Gland cells or goblet cell present on the epidermal layer of earthworms the function of these cells is to keep skin moist and slimy. Mucous cells and albumin cells are two types of gland cells. So this option is not correct.
The body of an earthworm consists of about 100-120 small pieces of rings, segments, or metameres. It shows the actual segmentation. Each segment of earthworm has bristles called seats . bristles help in holding a section of earth work firmly to the ground while other body parts produce forward segmentation providing strong and flexible movement to the earthworm Earthworms don't move unless each part is independent and moves together.

So, the correct option (C).

Note:
Earthworm is studied under the phylum Annelida of kingdom Animalia. Each segment, except first, last and clitellar segments, bear a ring of curved, chitinous structures known as setae. The size of earthworms varies from species to species and varies among individuals of the same species, and adult earthworms can reach 150 mm in length and 3-5 mm in width. The body consists of round holes ( annuli )and rings and 100 to 120 different segments or metameres. The latter are internally connected by partitions to divide the body cavity into compartments. This type of segmentation, whether external or internal, is known as true or metameric segmentation.