Annelida

Question 1

What is metamerism?

Answer 1

Metamerism isthe repetition of homologous body segments. This type of development can be seen in the Annelids, which include earthworms, leeches, tubeworms, and their relatives. It is also seen in a more advanced form in the Arthropods, such as crustaceans, insects, and their relatives.

Question 2

Give 4 characteristics of Annelids

Answer 2

1. They are triploblastic organisms (ectoderm, mesoderm, endoderm)
2. The body is metamerically segmented
3. The sexes are separate (Hemaphrodites)
4. The body is bilaterally symmetrical (left and right side of an organism equal)

Question 3

The excretory system of Annelids consists of

Answer 3

A pair of Nephridia is located in each segment.

Question 4

Give the classes of Annelids..

Answer 4

Class Polychaeta
Class Oligachaeta
Class Hirudilea

Question 5

The epidermis of Annelida is covered with

Answer 5

Thin Corticle.

Question 6

Annelids have a pre-oral segment known as

Answer 6

Prostonium in which the brain is located.

Question 7

Define Clitenium

Answer 7

Part of the body that is not segmented.

Question 8

What is parapodia?

Answer 8

any of the paired unjointed lateral appendages of polychaete worms, used in locomotion, respiration, etc.

Question 9

What are the characteristics of Class Polychaeta

Answer 9

1. They have distinct head but no clitenium(all body parts are segmented)
2. The lateral extension of their body is called Parapodia
3. They have sexes separate.

Question 10

Order Arenicola and Order Nereisis belong to what class

Answer 10

Class Polychaeta

Question 11

What are the characteristics of class Oligachaeta

Answer 11

1. They inhabit fresh water on earth
2. Parapodia is absent
3. Gonads are restricted in few segments of the body
4. Clitenium is present in matured worms
5. Members are hemephrodites
6. Sex organs are poorly developed

Question 12

What are the characteristics of Class Hirudinea(leeches)

Answer 12

1. Absence of chaeta
2. Members are hermaphrodite
3. The segments are few
4. There is no parapodia
5. There is at least one sicker
6. They are purely aquatic and are found in most freshwater bodies.