Annelida

Question 1

What is the phylum Annelida

Answer 1

is the segmented worms of the invertebrate animals

Question 2

The most common annelida

Answer 2

earthworm species Lumbricus terristris

Question 3

Structure of earthworms

Answer 3

The cylindrical body of the earthworm is darker on the dorsal side than on the vertical side
The anterior part of the body is tapered while the posterior part is blunt

Question 4

Structure of annelida

Answer 4

1. are bilaterally symmetrical
2. are coelomate which has allowed for the development of internal organs and a blood circulatory system
3. An alimantary canal has developed with specialised organs to aid with a more efficient digestive process
4. The through gut enables the organism to take in food continuously
5. Cephalisation occurs to such an extent that there is already a so called brain in the form of two dorsal nerve nodesat the antrior part of the animal

Question 5

The advantages of bilateral symmetry and cephalisation to the Annelida

Answer 5

the concentration of nerve tissue and sensory organs in the front means more efficient observation of stimuli as well as faster locomotion and better muscle coordination

Question 6

The disadvantages of bilateral symmetry to the Annelida

Answer 6

The organsim cannot react equally fast to stimuli in all directions because all the senses are concentrated at the front of the body

Question 7

The coelom of the earthworm

Answer 7

contains a watery fluid. the body flid (coelom fluid) sserves as a hydrostatic skeleton, as the muscles of the body continuously exert pressure on it. The advantage of such a hydrostatic skeleton is that it is very flexible

Question 8

What is prostomium?

Answer 8

Sensitive segment at the anterior end of the earthworm