47.1 Gastrulation

Question 1

gastrulation

Answer 1

where cells take up new locations that will allow the later formation of tissues and organs
-a dramatic rearrangement of cells of the blastula that produces a 3 layered embryo with a primitive digestive tube

Question 2

gastrula

Answer 2

embryo in gastrulation

Question 3

mechanisms that drive gastrulation

Answer 3

• change in cells motility-
• change in cell shape
• change in cellular adhesion to other cells and molecules of the extracellular matrix

Question 4

embryonic germ layers

Answer 4

ectoderm
mesoderm
endoderm

Question 5

gastrulation in a sea urchin

Answer 5

1) individual cells detach from the blastocoel wall and enter the blastocoel as migratory cells (mesenchyme cells)
2) remaining cells flatten a little and form a vegetal plate that buckles inward == (Invagination)
3) cells are rearranged and tube deeper and narrower to make -> (archenteron)
4) this open becomes anus later (blastopore)
5) second opening becomes the mouth later