Developmental Processes

Question 1

what is polarisation

Answer 1

form apical complex

driving force behind the first lineage restriction

Question 2

what cells become polarised

Answer 2

TE cells become polarised, while ICM cells lack apical/basal polarity

Question 3

what is asymmetric cell div

Answer 3

segregation of apical complex

Question 4

what sit he cell position

Answer 4

suppression of apical complex in inner cells

Question 5

what is cell fate

Answer 5

restricted expression of lineage sp genes

Question 6

what are the signalling centres

Answer 6

organiser
dorsal blastopore lip on ventral side of unpigmented host embryo
new neural tube
second embryo form

Question 7

what are signalling gradients

Answer 7

positional info

cells respond in sp way dept on conc of signal mol

Question 8

what do signalling gradients regulate

Answer 8

differentiation in the neural tube by providing positional info

Question 9

where is Shh prod

Answer 9

in notochord and floor plate

diffuses dorsally

Question 10

where is high levels Shh found

Answer 10

cells near floor plate

Question 11

when does Shh conc decrease

Answer 11

dorsally giving rise to diff cell types

Question 12

what happens if more Shh is added dorsally

Answer 12

change in cell fate due to and increase conc Shh

Question 13

what are dorsal cell after induced by

Answer 13

TGF(beta) signalling

opposes effects of Shh

Question 14

what does programmed cll death do

Answer 14

help shape embryo

Question 15

what does BMP4 signalling trigger

Answer 15

cell death programme in interdigital zones of foot and hand

Question 16

what do localised changes in shape in neuralation lead to

Answer 16

folding of neural plate at median an dorso-lateral hinge points

Question 17

where does tissue fusion occur

Answer 17

as edges of neural plate together

Question 18

what is imp for formation of face

Answer 18

tissue folding

Question 19

how many facial swellings

Answer 19

5

Question 20

when is there cell migration

Answer 20

gastrulation
neural crest
germ cells
interneurons

Question 21

what is epithelial cell state

Answer 21

cells in sheets with specialised mem contacts adherent and tight junctions

Question 22

what is mesenchymal cell state

Answer 22

loosely assc often motile cells with only transient focal attachments to other cells

Question 23

transition between epi cell state and mesenchymal cells state required for

Answer 23

gastrulation 
neural crest 
vertebrae
cardiac valves
secondary palate formation

Question 24

essentially what is `EMT

Answer 24

tissue remodelling

Question 25

what si the EMT pathwa

Answer 25

extra cell signals - signal mol and GF’s

transcription factors which repress key cell adhesion molecules

E- Cadherin caretaker of epi cell state

Question 26

what are 90% oral cancers have EMT

Answer 26

squamous cell carcinomas often characterised by low E-Cadherin expression