Intro lecture

Question 1

Baers laws

Answer 1

1. specialized characteristics occur in development, general characteristics are the first to appear
2. Special forms are developed from general forms
3. Every embryo of a given form doesn’t go through every other form, but into its own specialization
4. Final embryo of a higher form never resembles an embryo of a lower form

Question 2

What are the six stages of development

Answer 2

1. Cell division
2. Pattern emergence
3. Change in morphology
4. Cell differentiation
5. Growth
6. Death

Question 3

what are the three germ layers

Answer 3

Mesoderm, ectoderm, endoderm

Question 4

Define invagination

Answer 4

Infolding of cell sheet into embryo

Question 5

Define involution

Answer 5

Inturning of a cell sheet over the basal basal surface of the outer layer

Question 6

Define ingression

Answer 6

Migration of individual cells into the embryo

Question 7

Define delamination

Answer 7

Splitting or migration of one sheet into two sheets.

Question 8

Define epiboly

Answer 8

the expansion of one cell sheet over other cells

Question 9

Define condensation

Answer 9

Mesenchymal cells become epithelial cells

Question 10

Define migration

Answer 10

Cells move at particular times and places

Question 11

Matrix secretion and degradation

Answer 11

Synthesis or removal of extracellular label

Question 12

Define epithelial Dispersal

Answer 12

Epithelium becomes mesenchyme

Question 13

Define epithelial delamination

Answer 13

Parts of an epithelial layer disperse out to become mesenchymal cells

Question 14

Define epithelial cell migration

Answer 14

Rows of epithelia merge to form fewer rows

Question 15

Define epithelial migration

Answer 15

Formation of a free edge (the outside)