The body of earthworm can be distinguished into dorsal and ventral sides due to the presence of certain peculiar feature in it like.
(i) The dorsal surface is darker then ventral surface because it is marked by a dark median mid dorsal line along the longitudinal axis of body. This is due to dorsal blood vessel, seen through integument.
(ii) The ventral surface genital openings (pores), both male and female.
(iii) Genital papilla is located on ventral surface and help in copulation.
Correct the wrong statements among the following.
(a) In earthworm, a single male genital pore is present.
(b) Setae help in locomotion of earthworm.
(c) Muscular layer in the body wall of earthworm is made up of only circular muscles.
(d) Typhlosole is the part of intestine of earthworm.
Nephridia are the main excretory organs in earthworms. They are associated with excretory and osmoregulatory functions. The nephridia occur in all segments of earthworm except the first two segments. The three types of nephridia are found in earthworm according to their location.
They are distinguished on the basis of being enteronephric (nitrogen waste expelled input) and exonephric (nitrogen waste discharged outside directly).
Septal Nephridia These are present on both sides of inter segmental septa of the segment starting from 15th to the last that open into intestine. They are enteronephric.
Integumenatry Nephridia These are attached to lining of the body wall of segment 3 to the last that open on the body surface. They are exonephric.
Pharyngeal Nephridia These are present as a three paired tufts in the 4th, 5th and 6th segments. They are also enteronephric.
Common name of some animals are given in column I, write their scientific name in column II
| Column I | Column II | |
|---|---|---|
| A. | Tiger | ...................... |
| B. | Peacock | ..................... |
| C. | Hosefly | .................... |
A. Tiger - Panthera tigris
B. Peacock - Pavo cristatus
C. Housefly - Musca domestica
Complete the following statement.
(a) In cockroach grinding of food particle is performed by ............. .
(b) Malpighian tubules help in removal of .............. .
(c) Hind gut of cockroach is differentiated into ............ .
(d) In cockroach blood vessels open into spaces called .......... .
(a) Gizzard It is a muscular and greatly folded structure which marks the end of foregut and bears six plates with teeth for crushing and grinding the food.
(b) Malpighian tubules They help in the removal of nitrogenous wastes in arthropods, hence are excretory in function.
(c) Ileum, colon and rectum and rectum opens and through anus.
(d) Haemocoel It is the body cavity of cockroach divided into sinuses and contains visceral organs of cockroach floating in haemolymph.