Gene Regulation

Question 1

three aspects of development

Answer 1

differentiation, morphogenesis, growth

Question 2

differentiation

Answer 2

becoming a specialized cell

Question 3

morphogenesis

Answer 3

organism develops shape

Question 4

growth

Answer 4

cells divide or grow in size to make a bigger organism

Question 5

How are cells made different from each other?

Answer 5

cell-cell signaling and asymmetric division of cytoplasmic determinants

Question 6

cell-cell signaling

Answer 6

signaling molecules can be secreted to bind receptor on target cell or the signaling cell can have a molecule on the plasma membrane that binds adjacently to the target receptor

Question 7

sequential induction

Answer 7

a series of inductions results in new types of cells

Question 8

example of sequential induction

Answer 8

epiblast invaginates –> forms 3 layers –> mesoderm forms notochord –> notochord signals above ectoderm to form neuro-ectoderm

Question 9

bicoid gradient

Answer 9

regulates the A/P patterning in drosophila –> lots of bicoid in anterior and none in posterior

Question 10

asymmetric distribution

Answer 10

all of protein (determinants) segregate to one side so when cell divides, only one sister cell will get them

Question 11

example of asymmetric distribution

Answer 11

P-granules in C.elegans all go to posterior before first division

Question 12

totipotent

Answer 12

can produce all cells even placenta (fertilized egg)

Question 13

pluripotent

Answer 13

can be all cells except placenta (embryonic stem cell)

Question 14

multipotent

Answer 14

able to give rise to multiple cell types within the same lineage (hematopoietic stem cell)

Question 15

stem cells

Answer 15

can divide and differentiate into other types of cells; multiple types

Question 16

What controls the expression of genes?

Answer 16

epigenetics

Question 17

determination vs. differentiation

Answer 17

if a posterior region is transplanted to anterior before determination, the posterior will develop as anterior; if it is transplanted after determination, it will differentiate into posterior but in an anterior region

Question 18

ways to shape embryo

Answer 18

morphogenetic movements, changes in cell shape, cell matrix adhesions, intercellular adhesions, cell death, cell proliferation

Question 19

When does neurulation begin?

Answer 19

when the notochord induces the formation of the CNS by signaling to the above ectoderm to form the neural plate

Question 20

neuropores fail to close

Answer 20

spina bifida or anencephaly

Question 21

neural tube fails to close

Answer 21

craniorachischisis

Question 22

neuroectoderm

Answer 22

the region of ectoderm above the notochord –> will form the neural tube –> inhibits BMPs

Question 23

neural tube

Answer 23

will later differentiate into the spinal cord and brain

Question 24

ectoderm

Answer 24

signals to itself to remain ectoderm by secreting BMP4 and BMP7

Question 25

neurulation

Answer 25

medial hinge point forms above notochord –> undergo apical constriction to form neural groove –> two dorsolateral hinge points also undergo apical constriction forming a tube –> fusion –> neural crest cells migrate away, epidermis becomes top layer

Question 26

What level does neural tube folding begin?

Answer 26

around the level of the 4th somite at embryonic day 20

Question 27

BMP inhibitors

Answer 27

chordin, noggin, follistatin, Shh; secreted by notochord

Question 28

neural tube fusion

Answer 28

neural plate switches from E-cadherin expression to N-cadherin and N-CAM expression to prevent binding with ectoderm

Question 29

D/V patterning of neural tube

Answer 29

BMP in dorsal and Shh in ventral –> create a gradient

Question 30

What are mechanisms that control development?

Answer 30

cell signaling, morphogen gradient, TFs

Question 31

What is a developmental program?

Answer 31

series of developmental events where each event leads in a controlled way to more events until the life cycle has come full circle

Question 32

How does information processing occur?

Answer 32

transcription regulation and gene expression, signal transduction pathways, biochemical pathways, most cellular processes

Question 33

Where is the information for development?

Answer 33

DNA sequence and epigenetic marks, cellular and extracellular structure, womb and environment