Comparative nervous systems

Question 1

What specialised cell is found in sea sponges?

Answer 1

Myocyte- help control flow of water

Question 2

Features of non-segmented worm N.S

Answer 2

gangliation
clustering of neurons
fasciculation
commissures

Question 3

Features of segmented worm N.A

Answer 3

fusion of longitudinal nerve cords

brain evolved closely with mouth

Question 4

Shared feature of segmented and non-segmented worm N.S

Answer 4

Bilateral symmetry

Question 5

What cell do neurons share a lineage with in the C. Elegans?

Answer 5

dermis (skin)

Question 6

Stages of development of Drosophila N.S

Answer 6

1. Neurogenic region develops next to ectoderm
2. Migration of neurogenic region during gastrulation
3. Ectoderm delaminates (forming neuroblasts) and migrates inwards
4. Neuroblasts form ganglion mother cells, which form neurons and glia

Question 7

Features of vertebrate N.S development

Answer 7

1. Neurogenic region next to the ectoderm
2. Neurogenic region migrates downwards
3. Neurogenic region is next to the mesoderm- which involutes
4. Neural cells do not delaminate
5. Neural cells stay as a layer- neural plate