Concepts and Mechanism of Development

Question 1

4 developmental processes

Answer 1

Growth
Cytodifferentiation
Morphogenesis
Patterning

Question 2

4 developmental processes are all ___ and usually ___

Answer 2

interrelated
interdependent

Question 3

increase in the size of a part or the entirety of the organism by increasing cellular size (hypertrophy) and/or number of cells (hyperplasia)

Answer 3

Growth

Question 4

growth is not proportionate in all body parts

Answer 4

Allometric growth

Question 5

growth rate of all body parts of the body occurs at the same rate as the overall growth of the body

Answer 5

Isometric growth

Question 6

mechanism by which tissues and organs are shaped

Answer 6

Morphogenesis

Question 7

process whereby embryonic cells organize into tissues and organs

consequence of regional gene expression

Answer 7

Patterning

Question 8

formation of the cranio-caudal axis comes with ___, whereas the proximo-distal axis is ___ until limb formation

Answer 8

gastrulation

delayed

Question 9

process whereby specialized cell types from less specialized

Answer 9

Cytodifferentiation

Question 10

an event preceding cell differentiation

Answer 10

cell commitment

Question 11

*cell commitment

divided into labile, reversible phase referred to as

Answer 11

cell specification

Question 12

*cell commitment

followed by an irreversible one called

Answer 12

cell determination

Question 13

process when embryonic stem cells commit to one specialized function

Answer 13

cell determination

Question 14

process in which cells develop their specialzed shapes and function

Answer 14

cell differentiation

Question 15

a cell is fixed and it will irrevocably differentiate

Answer 15

cell determination

Question 16

ability of the cells to produce all the differentiated cells in the body

Answer 16

totipotency

Question 17

developmental potential

Answer 17

potency

Question 18

having equal effects or capacities

Answer 18

equipotent

Question 19

cells individually give rise to all cells of the embryo proper

Answer 19

cellular totipotency

Question 20

ICM and epiblast, retain the ability to form all tissues of the embryo proper but lose competence to form extra embryonic tissues

Answer 20

pluripotency

Question 21

cells within each of these somatic germ layers

Answer 21

multipotent

Question 22

tissues specific progenitor or precursor cells

Answer 22

unipotent

Question 23

fully matured and no longer divide

Answer 23

terminally differentiated

Question 24

process by which tissue interact with other tissues in the body

failure to interact may result to non development of a certain tissue or organ

Answer 24

tissue interaction

Question 25

occur by ___ - interaction at close range between two or more cells

Answer 25

induction (proximate interaction)

Question 26

the group that controls the differentiation of the other group -optic vesicle induce the lens formation from the surface ectoderm

Answer 26

inducing cells

Question 27

the dependent group when the optic vesicle was removed, no lens was formed

Answer 27

induced cells

Question 28

ability to respond to a specific inductive signal

Answer 28

competence

Question 29

genetically programmed death of cells in the interdigital zone/necrotic zone for the normal development of the digits

Answer 29

apoptosis

Question 30

principal intracellular mediators of apoptosis

Answer 30

caspases

Question 31

those carried in the genes which are either caused by a single or multiple genes

Answer 31

intrinsic/hereditary factors

Question 32

*Congenital malformations caused by an extra 21st chromosome (trisomy 21) - may result to heart defects

Answer 32

down syndrome

Question 33

those caused by teratogens

Answer 33

extrinsic/non hereditary factors

Question 34

those agents that caused induced birth defects

Answer 34

teratogens

Question 35

targets the ectoderm, hence defects arise from this germ layer

Answer 35

virus-rubella (german measles)

Question 36

medicines for virus-rubella (german measles)

Answer 36

-thalidomide (Thalomid), angiotensin- converting enzyme (ACE) inhibitors, statins, the acne medication isotretinoin and lithium.

Question 37

The teratogens that enter the the mother via the ____ or ____, the actual teratogenic effect can either be modified to lessen the effect or to be more embryopathic as a product of maternal metabolism

Answer 37

digestive tract or placenta

Question 38

the most critical period of most structures is during ___ and ___ - at this stage the issues are the most sensitive to disruption by exogenous factors

Answer 38

blastula and gastrula

Question 39

 ____ and ____ are sensitive to teratogenic insult throughout prenatal and even postnatal in most species  This is due to late development of the neurons in the cerebrum and cerebellum

Answer 39

CNS and heart

Question 40

 At neurula stage few organs will be affected  Oftentimes, an induced lesion in one system will result in the ____ in other organs

Answer 40

secondary malformations

Question 41

____, ____ and ____ (behavioral teratogens) cause irreversible defects in cognitive and motor dev’t.

Answer 41

tranquilizers, sedatives and anticonvulsants