molecular genetics and early embryonic development

Question 1

cells begin to form specific and specialized structures

Answer 1

differentation

Question 2

cell divisions that form more cells with identical functions as the parental cell

Answer 2

growth

Question 3

cells produced by cleavage get organized into layers and groups of cell masses through what is known as gastrulation

Answer 3

patterning

Question 4

patterning needs to occur in 3 dimensions:

Answer 4

anterior-posterior (top-bottom)
dorsal-ventral (left-right)
proximal-distal (front-back)

Question 5

craniofacial anomalies account for ____ of all congentical defects

Answer 5

1/3

Question 6

not sensitive usually, high rate of lethality may occur

Answer 6

0-3 weeks

Question 7

period of greatest sensitivity and each organ system will also have a period of peak sensitivity

Answer 7

3-8 weeks

Question 8

decreasing sensitivity and period of functional maturation

Answer 8

9-38 weeks

Question 9

multicellular organisms are enriched in :

Answer 9

proteins mediating cell interactions and gene regulation

Question 10

this defines the development program

Answer 10

regulatory DNA

Question 11

this division is where sister cells are born different

Answer 11

asymmetric division

Question 12

this division is where sister cells become different as a result of influences acting on them after birth

Answer 12

symmetric division

Question 13

-start point (cell or cell cluster)
-cell to cell signaling
-cell signaling cascades
-acts over great distance

Answer 13

inductive signaling

Question 14

early developmental process in which the embryo (week 3) transforms from a single cell layer (blastula) into the three primary germ layers which are known as

Answer 14

gastrulation

ectoderm
endoderm
mesoderm

Question 15

embryonic cell population that is localized between the developing neural tube and the epidermis

Answer 15

neural crest cells

Question 16

some neural crest cells exhibit this in that they can give rise to multiple differentiated cell types

Answer 16

stemness

Question 17

in the formation of the craniofacial structures, these cells migrate through restricted pathways to form the developing structures

Answer 17

neural crest cells

Question 18

cell migration is a tightly regulated process and the neural crest cells receive cues such as ______ and ______ that restrict their movements and determine fate

Answer 18

morphogens and growth factors

Question 19

> 100 different disorders and commonly involves one or more of teeth, nails, skin, sweat glands and or hair

Answer 19

ectodermal dysplasias

Question 20

missing a few teeth

missing more than 6 teeth

missing all teeth

Answer 20

hypodontia

oligodontia

anodontia