Morphogenesis

Question 1

What are the 3 germ layers; what structures do they form?

Answer 1

Ectoderm: epidermis of skin, nervous system
Mesoderm: skeleton, muscle, kidney, heart, blood
Endoderm: gut, liver, lungs

Question 2

3 stages of gastrulation (in sea urchin)

Answer 2

• Movement of endoderm and mesoderm inside the embryo
• Formation of a gut
• Main body plan emerges

Question 3

Where do germ cells move?

Answer 3

To somatic tissue

Question 4

What does isolating blastomeres at the 4 cell stages in sea urchins result in?

Answer 4

4 small larvae

Question 5

What does isolation the animal/vegetal halves at the 8 cell stage result in?

Answer 5

Abnormal embryos

Question 6

Define neurulation

Answer 6

Formation of neural tube

Neural plate on embryo surface sinks to form a neural groove and the edges start to rise up and fuse togehter