Pre-gastrulation

Question 1

process by wherein the developmental trajectory of a tissue or organ is affected by the presence of a neighboring group of cells

Answer 1

cellular induction

Question 2

t or f: cellular induction usually results in changes in gene expression and cell behavior

Answer 2

t

Question 3

t or f: cellular induction involves signals that bind to receptors to begin the signal transduction pathway

Answer 3

t

Question 4

it is the ability of a cell to respond to induction

Answer 4

competence

Question 5

it is the ability to sense and respond to chemical signals

Answer 5

competence

Question 6

it is the ability of a cell to respond to external factors

Answer 6

competence

Question 7

t or f: before a responder can respond, it should be competent

Answer 7

t

Question 8

t or f: morphogens act over short distances

Answer 8

f; long

Question 9

how do different tissues respond to a signal

Answer 9

• incompetent
• competent and correct
• competent and incorrect

Question 10

induction may either be: (types of induction)

Answer 10

permissive and instructive

Question 11

a type of induction wherein the responder contains all the potentials that are to be expressed, and needs only an environment that allows the expression of these traits

Answer 11

permissive interaction

Question 12

a type of induction wherein a signal from the inducing cell is necessary for initiating new gene expression in the responding cell

Answer 12

instructive interaction

Question 13

two types of instructive interaction

Answer 13

• appositional
• morphogen gradient

Question 14

it is an instructive interaction wherein there must be a close interaction with the tissues to allow the expression to happen

Answer 14

appositional interaction

Question 15

what are the types of cell-to-cell communications?

Answer 15

• autocrine
• signaling across gap junctions
• paracrine
• endocrine

Question 16

a form of chemical signaling wherein a cell targets itself

Answer 16

autocrine

Question 17

a form of chemical signaling wherein a cell targets a cell connected by gap junctions

Answer 17

signaling across gap junctions

Question 18

a form of chemical signaling wherein a cell targets a nearby cell

Answer 18

paracrine

Question 19

a form of chemical signaling wherein a cell targets a distant cell thru the bloodstream

Answer 19

endocrine

Question 20

t or f: in the signal transduction pathway, the chemical messengers can only enter the target cell via diffusion

Answer 20

f; it can enter via receptor binding as well

Question 21

t or f: the nature of the ligand cannot affect the type of signal transduction

Answer 21

f

Question 22

which chemical signaling is considered long lasting

Answer 22

endocrine

Question 23

which chemical signaling is considered short-lasting

Answer 23

paracrine

Question 24

t or f: an H2O ligand can diffuse into the membrane

Answer 24

f

Question 25

t or f: a fat-soluble ligand can diffuse into the membrane

Answer 25

t

Question 26

it is the transmission of molecular signals from the cell's exterior to its interior and is also known as cell signaling

Answer 26

signal transduction

Question 27

what happens to fat-soluble ligand when it enters the cell?

Answer 27

there is an intracellular binding of receptor

Question 28

t or f: cell-to-cell interactions does not need an environment to initiate responses

Answer 28

f

Question 29

t or f: the ECM is a homogenous structure

Answer 29

f

Question 30

different components of the ECM

Answer 30

- proteoglycans - fibronectin - laminin

Question 31

structure that supports the tissue and cell

Answer 31

ECM

Question 32

t or f: if tissue shape changes, ECM changes

Answer 32

t

Question 33

example of developmental stage wherein ECM is helping

Answer 33

neural fold formation; ECM needs to change to raise the neural plate

Question 34

multiple functional roles of the ECM in various biological processes

Answer 34

- functions as adhesive substrate - provides structure - presents growth factors to their receptors - sequesters and stores growth factors - senses and transduces mechanical signals

Question 35

an ECM component that is responsible for the delivery of paracrine factors

Answer 35

proteoglycans

Question 36

pathway involved in heparan sulfate, a proteoglycan

Answer 36

FGF pathway

Question 37

t or f: if proteoglycan synthesis is blocked, normal cell migration, morphogenesis, and differentiation will still take place

Answer 37

f

Question 38

two examples of proteoglycans

Answer 38

heparan sulfate and chondroitin sulfate

Question 39

a glycoprotein which serves as a general adhesive molecule

Answer 39

fibronectin

Question 40

a glycoprotein which paves the roadway

Answer 40

fibronectin

Question 41

explain the fibronectin assembly

Answer 41

- folded configuration of FBN binds to integrin alpha 5 beta 1dimer - FBN exerts effort to ECM dimer - FBN elongate or unfold - fibrin acts as roads for cells

Question 42

what happens to FBN once it binds to integrin alpha 5 beta 1 dimer?

Answer 42

FBN sites are exposed for fibril formation

Question 43

it involves the changes in the configuration of FBN

Answer 43

fibrillogenesis

Question 44

an ECM component which is aka the basement protein

Answer 44

laminin

Question 45

sites wherein laminin is degraded

Answer 45

- lungs - pancreas - mammary gland branching

Question 46

t or f: laminin interacts with receptors in cells immediately neighboring the basement membrane

Answer 46

t

Question 47

t or f: laminin must be removed to remodel the tissue

Answer 47

t

Question 48

an ECM component that acts as tissue foundation

Answer 48

laminin

Question 49

multiple factors presented by the ECM that can regulate cell behaviors

Answer 49

- topography - fiber and pore size - fiber orientation - fiber elasticity - ligand density - basement membrane - fibrous ECM

Question 50

ECM factor which allows cells to invade through gaps

Answer 50

fiber and pore size

Question 51

fiber can be elastic because of what protein?

Answer 51

elastin

Question 52

fiber can be rigid because of what protein?

Answer 52

collagen

Question 53

ECM factor which affects the extent of cell spreading

Answer 53

ligand density

Question 54

a transmembrane protein which mediates cell-to-cell adhesion

Answer 54

cadherins

Question 55

principal receptors used by cells to bind to the ECM

Answer 55

integrins

Question 56

different junctional complexes that connect cells

Answer 56

- tight junction - anchoring junction - gap junction

Question 57

types of anchoring junctions

Answer 57

- adhering junctions - desmosome - hemidesmosome

Question 58

main protein of tight junction

Answer 58

claudins

Question 59

t or f: cell adhesion molecules underlie all types of cellular junctions

Answer 59

t

Question 60

it is a protein domain that mediates the binding of the cell to environment or other cells

Answer 60

extracellular domain

Question 61

it is a protein domain that passes through the plasma membrane

Answer 61

transmembrane domain

Question 62

it is a protein domain which interacts with cytoskeleton

Answer 62

intracellular domain

Question 63

a type of cadherin needed for the formation and migration of the epiblast as a sheer during gastrulation

Answer 63

E-cadherin

Question 64

a type of cadherin that helps the placenta stick on the uterus

Answer 64

P-cadherin

Question 65

a type of cadherin that is highly expressed on the cells of the developing CNS

Answer 65

N-cadherin

Question 66

a type of cadherin that is critical in retina formation

Answer 66

R-cadherin

Question 67

mutation in this cadherin leads to neural tube defects

Answer 67

N-cadherin

Question 68

mutation in this cadherin leads to epiboly defects

Answer 68

E-cadherin

Question 69

t or f: cadherins exhibit a heterophilic interaction

Answer 69

f; homophilic

Question 70

t or f: cadherins are necessary for development

Answer 70

t

Question 71

the downregulation of this cadherin led to a defective male-pattern development in mice

Answer 71

N-cadherin

Question 72

integrin signaling wherein intracellular activator binds to induce conformational change and increased affinity for extracellular ligands

Answer 72

inside-out signaling

Question 73

integrin signaling wherein the ligand binds outside of the integrin inducing integrin clustering

Answer 73

outside-in signaling

Question 74

what happens when a ligand bind to integrin in outside-in signaling?

Answer 74

there is activation of signal cascade which leads to intracellular signals

Question 75

what happens to unligated integrins?

Answer 75

induce apoptosis

Question 76

t or f: integrins do not function in cell signaling

Answer 76

f

Question 77

steps in mesenchymal cell migration

Answer 77

- the cell is attached to the ECM via integrins and FA - actin polymerization at the leading edge extends filamentous actin protrusions including a front-rear polarization - new FA adhesions attach the protrusions to the ECM followed by F-actin rearward movement aka actin retrograde flow - disassembly of rear FA and myosin II contraction at the back of cell generate the pushing force

Question 78

steps in amoeboid cell migration

Answer 78

- no adhesions formed - formation of membrane blebs aka pseudopodia inducing a front-rear polarization - actin retrograde flow is initiated by mechanical forces like confinement - myosin II contraction to push the cell forward

Question 79

adhesion-maturation process

Answer 79

- focal complexes - focal adhesions - fibrillar adhesions

Question 80

focal adhesions will mature into

Answer 80

fibrillar adhesions

Question 81

it is the ECM-bound cell migration

Answer 81

mesenchymal

Question 82

it is the ECM-free cell migration

Answer 82

amoeboid

Question 83

it is the first detectable cell-ECM adhesion in cell migration

Answer 83

focal complex

Question 84

t or f: fibrillar adhesion is easy remove

Answer 84

f

Question 85

the structure that contracts in cell migration

Answer 85

myosin II

Question 86

category of cell migration that is important in morphogenesis

Answer 86

collective cell migration

Question 87

types of amoeboid migration

Answer 87

- blebby - pseudopodal

Question 88

categories of cell migration

Answer 88

- single cell migration - collective cell migration

Question 89

difference between single cell migration and collective cell migration

Answer 89

collective cell migration involves cell-cell adhesions

Question 90

types of collective cell migration

Answer 90

- epithelial - mesenchymal

Question 91

t or f: epithelial cell migration has weaker cell-cell adhesion compared to mesenchymal cell-cell adhesion

Answer 91

f

Question 92

purpose of stable cell-cell adhesion in epithelial collective cell migration

Answer 92

to fulfill its barrier function

Question 93

t or f: mesenchymal collective migration has transient cell-cell adhesion

Answer 93

t

Question 94

it is when certain group of cells preferentially mix with similar cell types

Answer 94

differential cell affinity

Question 95

t or f: cells with more cadherins have lower surface cohesion

Answer 95

f; higher surface cohesion

Question 96

t or f: cells with more cadherins migrate internally

Answer 96

t

Question 97

t or f: differential cell affinity can contribute to the formation of distinct cell groups

Answer 97

t

Question 98

t or f: cells rearrange in the most thermodynamically stable pattern

Answer 98

t

Question 99

t or f: cells may also differentially segregate based on the type of adhesion

Answer 99

t

Question 100

t or f: cells can sort based on difference in adhesion strengths

Answer 100

t