Molecular Genetics and Early Embryonic Development

Question 1

What are the stages of embryonic development

Answer 1

• differentiation
  -growth
• patterning

Question 2

what is differentiation

Answer 2

cells form specific and specialized structures

Question 3

what is growth

Answer 3

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

Question 4

what is patterning

Answer 4

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

Question 5

what 3 dimensions does patterning need to occur in

Answer 5

-anterior posterior
- dorsal ventral
- proximal and distal

Question 6

what are the malocclusion syndromes

Answer 6

-pierre robin
-treacher collins
-marfan syndrome

Question 7

what are the craniofacial malformations

Answer 7

-crouson
- apert
- pfeiffer
-clefting syndromes

Question 8

what are the bone mass traits

Answer 8

-sclerosteosis and van Buschem’s
- high bone mass and OPPG
- Pagets disease

Question 9

craniofacial anomalies account for ~______ of all congential defects

Answer 9

1/3

Question 10

when is the risk highest for teratogenesis and lowest

Answer 10

3-8 weeks is the highest, 9-38 is the lowest

Question 11

what is meant by universal mechanisms of animal development

Answer 11

species share signal proteins and receptors in common

Question 12

what defines the development program

Answer 12

regulatory DNA

Question 13

what are multicellular organisms enriched with

Answer 13

proteins mediating cell interactions and gene regulation

Question 14

what is inductive signaling and morphogens

Answer 14

gradients reflective of a balance between postive and inhibitory signals or sequential induction

Question 15

what is the difference between asymmetric and symmetric division

Answer 15

• asymmetric division- sister cells born different
• symmetric division- sister cells become different as a result of influences acting on them after their birth

Question 16

describe inductive signaling

Answer 16

• theres a starting point: cell or cell cluster
• cell- cell signaling
• cell signaling cascades
• acts over great distances

Question 17

what is gastrulation

Answer 17

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

Question 18

what are the three primary germ layers

Answer 18

ectoderm, endoderm, mesoderm

Question 19

race and ethnicity are _____. they do not exist ____.

Answer 19

social constructions; biologically

Question 20

what is a race

Answer 20

a socially defined category based on real or perceived biological differences between groups of people

Question 21

what is ethnicity

Answer 21

a socially defined category based on common language, religion, nationality, history or another cultural factor

Question 22

what are social epigenomics

Answer 22

the impact of social and environmental factors and how that manifests biologically through genetic changes in response to those stresses

Question 23

the stresses dont change the ______ but they affect _____

Answer 23

underlying human genome; gene expression

Question 24

what percentage of all births exhibit some form of a craniofacial syndrome

Answer 24

3%

Question 25

what does craniofacial development include

Answer 25

• neural tube development and closure
• formation of ectoderm, somites, mesoderm and other cell masses
• neural crest cell development, differentiation and migration
• tissue- tissue interactions
• tissue specific patterns of gene expression
• reciprocal induction.
• growth and mineralization of bones and teeth
• neural development
• muscle development

Question 26

what are neural crest cells

Answer 26

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

Question 27

what do some neural crest cells exhibit and what is this

Answer 27

stemness- they can give rise to multiple differentiated cell types

Question 28

how do neural crest cells migrate to form developing structures

Answer 28

through restricted pathways under a tightly regulated process and receive cues such as morphogens and growth factors that restrict their movement and determine fate

Question 29

what are the 5 key development signaling pathways

Answer 29

-RTK
- TGF beta
- Wnt
- Hedgehog
- Notch

Question 30

how many genes have been identified that have mutations associated with tooth patterning, morphogenesis defects and cell differentiation defects

Answer 30

300

Question 31

what are ectodermal dysplasias and how many are there

Answer 31

• over 100 different disorders
• commonly involves one or more teeth, nails, skin, sweat glands and/or hair

Question 32

what is hypodontia

Answer 32

missing only a few teeth

Question 33

what is oligodontia

Answer 33

missing more than 6 teeth excluding third molars

Question 34

what is anodontia

Answer 34

absence of teeth

Question 35

what is microdontia

Answer 35

one or more teeth appear smaller

Question 36

what is macrodontia

Answer 36

one or more teeth grow faster and excess average size

Question 37

what are the key signaling pathways in tooth development

Answer 37

oral ectoderm -> dental mesenchyme -> dental placode -> condesned dental mesenchyme -> enamel knot -> dental papilla

Question 38

what drives tooth formation

Answer 38

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