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Flashcards in Genetics of Development Deck (43)
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1
Q

regulative phasee

A

cells are functionally equivalent and loss of a part of embryo can be compensating for by neighboring similiar cells

2
Q

mosaic phase

A

a loss of cell cannot be compensated

3
Q

what are the 3 axes in the embryo

A

anterior postier
dorsal ventral
left right

4
Q

what axes is the first visible structure in the embryo

A

anterior posterio

5
Q

what does extoderm form

A

skin and nerovus system

6
Q

what does mesoderm form

A

bones, muscle, internal organ

7
Q

what does endoderm form

A

cells of gut and leng epithlum

8
Q

what proteins specify dorsal;/ventral axis

A

noggin and chordin

9
Q

what signaling protein causes left right asymmetry

A

sonic hedgehog

10
Q

hodal

A

initated the left looping of the heart tube

11
Q

situs inverstus

A

organs are the mirror image of what they are supposed to be

12
Q

situs ambiguus

A

orientation of the organs is radmosized

13
Q

shoulder to fingertep is

A

proximal distal

14
Q

thumb to 5th finger is

A

anterior posterio

15
Q

dorsum to palm is

A

dorsal ventral

16
Q

patterning along the anteior/posterio axis is determined by waht

A

HOX genes

17
Q

what do HOX genes contain

A

DNA binding domain called homeodomain

18
Q

;what are the 5 mechanisms operating in development

A

gene regulation by transcription factors and chromatin modifation
cell-cell signalling
development of specific cell shape and polarity
movement and migration of cells
programmedc ell death

19
Q

malformation

A

intrinsic abnoramlity in the developmental process -

20
Q

example of malformation

A

polydactylyl

21
Q

deformation

A

extrinsic influence on teh development of affected tissue

22
Q

example of deformation

A

lack of aminiotic fluid puts contstraite on fetus

23
Q

disruption

A

destruction of developing tissue

24
Q

example of disruption

A

amniotic bands wrap aroun dfetal limbs

25
Q

isolated anomlaie

A

affect a single body region (cleft palet)

26
Q

sequence

A

cascase of events that leads to multiple malformations

27
Q

syndrome

A

affect several body regions and most often display chromosomal or mendelian inherence

28
Q

a squence is present when

A

disease phenotypes are caused sequentially by a single defect

29
Q

a syndrome is present when

A

all of the disease phenotypes are caused by a single defect simultaneously

30
Q

how are anomalies classied

A

stage of development when the defect happened

31
Q

abnoramlity oxxuring during the first 1-4 weeks of development prodcue what

A

multiple major abnormalities in entire embryonic regions

32
Q

abnoramlities occuring from week 5 to week 8 produce waht

A

affect specific organs and produce single major anomalies

33
Q

abnoramlies occurring after week 9 affect what

A

mild effect

34
Q

major anomaliy

A

have surgical or cosemntic conseuqnces

35
Q

mino anomalies

A

have little impact on well -being of pt

36
Q

what percentage of children are born with a recognizable birth defect

A

2-3%

37
Q

how many infant deaths are caused by prematurity

A

20%

38
Q

how comman afer heart defects

A

1/100 -1/200 live births

39
Q

how common is pyloric stenosis

A

1/300

40
Q

how common is neural tube defect

A

1/1000

41
Q

how common is orofacial cleft

A

1/700 - 1/1000

42
Q

how common is clubfoot

A

1/1000

43
Q

what are teh msot frequenct identifable cuase for birth defect

A

genetic defect