Concepts and Mechanism Development

Question 1

What are the processes that take place during early developmental stages? (5)

Answer 1

growth, morphogenesis, patterning, cytodifferentiation, tissue interaction

Question 2

programmed degeneration & eventual death of
cells in areas called necrotic zones

Answer 2

normal cell death or apoptosis

Question 3

outward folding or outpocketing of the epithelium

Answer 3

evagination

Question 4

downward migration of epithelium with secondary, tertiary branches given off from the main branch

Answer 4

budding and branching

Question 5

separation of an invaginated epithelium from the original epithelium; the second stage in more complex morphogenetic reorganization

Answer 5

vesicle formation

Question 6

it is the infolding or depression of epithelium to form a pit or groove; often the first stage in more complex morphogenetic reorganization

Answer 6

invagination

Question 7

focal thickening of surface ectoderm, often in response to an underlying mesenchymal aggregation. Ex. formation of eye lens from lens placode and inner ear from auditory placode

Answer 7

placode formation

Question 8

elongation of epithelial cells

Answer 8

epithelial expansion

Question 9

migration of epithelial cells to the underlying area to form mesenchymal cells

Answer 9

delamination

Question 10

grouping of mesenchymal cells to form a densely packed subpopulation within a mesenchymal tissue

Answer 10

mesenchymal aggregation

Question 11

refers to the increase in the number or size of cells that results in the increase in
mass of the organism

Answer 11

growth

Question 12

establishment of invisible blueprint of cell
subpopulations that serves as a guide in the formation of a particular tissue or organ

Answer 12

patterning/pattern formation

Question 13

complex tortuous process by which each cell or cell line attains and expresses a stable phenotype or a process by which a cell becomes specialized and the final product is a differentiated cell

Answer 13

cytodifferentiation

Question 14

a group of cells predestined to develop into a specific tissue or organ

Answer 14

stable phenotype

Question 15

a process in which the presence of one tissue
or structure induces or causes the development of another tissue or structure

Answer 15

tissue interaction/induction

Question 16

time during which each organ system in the body is being formed and obligatory inductive tissue interactions and morphogenesis are occurring

Answer 16

critical period

Question 17

What are the two fundamental inductive event that takes place during gastrulation?

Answer 17

primary inductions and secondary inductions

Question 18

are a series of events that have cumulative effects and may occur long before the final establishment of a cell’s phenotype

Answer 18

inductive tissue interactions

Question 19

These are abnormalities present at birth that
result from errors arising during development. What are the causes?

Answer 19

Congenital Malformation or Congenital Defects
a. hereditary or genetic factors
b. environmental factors

Question 20

induces birth defects during closure of neural tube resulting in eye, brain and heart defects

Answer 20

Hypo- and hypervitaminosis A

Question 21

study of induced birth defects

Answer 21

teratology

Question 22

teras means?

Answer 22

monster

Question 23

condition in which a specific congenital abnormality will occur with higher incidence in a specific breed of animal, but is not attributable to an identifiable single-gene defect

Answer 23

breed predilection

Question 24

genes that cause congenital defects

Answer 24

deleterious genes