Genetics of Development

Question 1

regulative phasee

Answer 1

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

Question 2

mosaic phase

Answer 2

a loss of cell cannot be compensated

Question 3

what are the 3 axes in the embryo

Answer 3

anterior postier
dorsal ventral
left right

Question 4

what axes is the first visible structure in the embryo

Answer 4

anterior posterio

Question 5

what does extoderm form

Answer 5

skin and nerovus system

Question 6

what does mesoderm form

Answer 6

bones, muscle, internal organ

Question 7

what does endoderm form

Answer 7

cells of gut and leng epithlum

Question 8

what proteins specify dorsal;/ventral axis

Answer 8

noggin and chordin

Question 9

what signaling protein causes left right asymmetry

Answer 9

sonic hedgehog

Question 10

hodal

Answer 10

initated the left looping of the heart tube

Question 11

situs inverstus

Answer 11

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

Question 12

situs ambiguus

Answer 12

orientation of the organs is radmosized

Question 13

shoulder to fingertep is

Answer 13

proximal distal

Question 14

thumb to 5th finger is

Answer 14

anterior posterio

Question 15

dorsum to palm is

Answer 15

dorsal ventral

Question 16

patterning along the anteior/posterio axis is determined by waht

Answer 16

HOX genes

Question 17

what do HOX genes contain

Answer 17

DNA binding domain called homeodomain

Question 18

;what are the 5 mechanisms operating in development

Answer 18

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

Question 19

malformation

Answer 19

intrinsic abnoramlity in the developmental process -

Question 20

example of malformation

Answer 20

polydactylyl

Question 21

deformation

Answer 21

extrinsic influence on teh development of affected tissue

Question 22

example of deformation

Answer 22

lack of aminiotic fluid puts contstraite on fetus

Question 23

disruption

Answer 23

destruction of developing tissue

Question 24

example of disruption

Answer 24

amniotic bands wrap aroun dfetal limbs

Question 25

isolated anomlaie

Answer 25

affect a single body region (cleft palet)

Question 26

sequence

Answer 26

cascase of events that leads to multiple malformations

Question 27

syndrome

Answer 27

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

Question 28

a squence is present when

Answer 28

disease phenotypes are caused sequentially by a single defect

Question 29

a syndrome is present when

Answer 29

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

Question 30

how are anomalies classied

Answer 30

stage of development when the defect happened

Question 31

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

Answer 31

multiple major abnormalities in entire embryonic regions

Question 32

abnoramlities occuring from week 5 to week 8 produce waht

Answer 32

affect specific organs and produce single major anomalies

Question 33

abnoramlies occurring after week 9 affect what

Answer 33

mild effect

Question 34

major anomaliy

Answer 34

have surgical or cosemntic conseuqnces

Question 35

mino anomalies

Answer 35

have little impact on well -being of pt

Question 36

what percentage of children are born with a recognizable birth defect

Answer 36

2-3%

Question 37

how many infant deaths are caused by prematurity

Answer 37

20%

Question 38

how comman afer heart defects

Answer 38

1/100 -1/200 live births

Question 39

how common is pyloric stenosis

Answer 39

1/300

Question 40

how common is neural tube defect

Answer 40

1/1000

Question 41

how common is orofacial cleft

Answer 41

1/700 - 1/1000

Question 42

how common is clubfoot

Answer 42

1/1000

Question 43

what are teh msot frequenct identifable cuase for birth defect

Answer 43

genetic defect