Annelida 1

Question 1

intro

3 points

Answer 1

1. Segmented worms
2. Global distribution
3. Occupy all major habitat types

Question 2

Classification

Answer 2

Kingdom: metazoa

Phylum: Annelida

Class: Polychaeta, Clitellata

Question 3

Key characteristics

7 points

Answer 3

1. Bilaterally symmetrical and vermiform
2. Segmented with growth from teloblasts
3. Trimeric or tripartite
   Triploblastic (ectoderm, mesoderm and endoderm)
4. Tissues, organs and closed circulatory system

Respiratory pigments (haemoglobin, chlorocruorin and hemerythrin)

5. Nervous system
   Wide array of sensory receptors
   Dorsal cerebral ganglion or simple brain
6. Lateral, epidermal chaetae
7. Gonochoristic or hermaphroditic
   Trochophore larva

Question 4

Body structure

5 points

Answer 4

1. Trimeric
   Prostomium (palps, tentacles, cirri, caruncle, nuchal organ)
   Peristomium (mouth, tentacles, palps)
   Pygidium (anus, telobasts)

2. Body wall 
Cuticle
Epidermis 
Connective tissues
Muscles
Peritoneum lines coelom

3. Coelom
   Laterally paired
   Hydrostatic skeleton
4. Metameres
   Separated by septa (intact, secondarily lost, perforated)
   Homonymous and heteronomous metamery
5. Parapodia
   Biramous
   Notopodium and neuropodium contain chaetae
   Locomotion, gas exchange, protection, anchorage and water flow

Question 5

Locomotion (errant)
Walking/Crawling
4 points

Answer 5

1. Metachronal or peristaltic wave
2. Parapodia
3. Chaetae
4. Limited contact with surface

Question 6

Locomotion (errant)
Burrowing
3 points

Answer 6

1. Peristaltic movement
2. Anchorage
3. Fracturing, fluidising and eating

Question 7

Locomotion (errant)

2 others

Answer 7

Swimming

Boring

Question 8

Locomotion (sedentary)

Answer 8

1. Tube-dwelling
Protection
Built from base of peristomium 
Secretions (calcium carbonate, organic, chitin)
Biogenic structures

Question 9

Reproduction (sexual)

4 points

Answer 9

1. Dioecious
2. External fertilisation
3. Indirect development
4. Trochophore larva

5. Internal fertilisation
Copulation
Clitellum
Mixed development
Egg brooding

6. Hermaphrodites
   Clitellata
   Direct development

Question 10

Reproduction (asexual)

5 points

Answer 10

1. Fragmentation
   Growth from individual segments
2. Budding
3. Chaining
4. Direct growth from segments
5. Neurosecretory control

Question 11

Regeneration

5 points

Answer 11

1. Various degrees of regeneration
   Palps, tentacles, cirri and parapodia
2. Posterior regeneration common
3. Anterior regeneration (head) limited
4. Controlled by nervous system
   Neuroendocrine secretions
5. Blastema