Concepts and Mechanism of Development

Question 1

Processes that take place during early developmental stages

Answer 1

1. Growth
2. Morphogenesis
3. Patterning
4. Cytodifferentiation
5. Tissue Interaction

Question 2

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

Answer 2

growth

Question 3

means that there are different rates of growth of the same kinds of tissue

Answer 3

growth of embryo is differential

Question 4

Embryo increases in size due in what reason?

Answer 4

• SPREAD or dispersal of mitotic cells
• PRODUCTION of extracellular materials
• ACQUISITION of specifications by cells

Question 5

refers to the entire group of processes that mold the external and internal configuration of the embryo.

Answer 5

Morphogenesis

Question 6

elongation of epithelial cells

Answer 6

epithelial expansion

Question 7

migration of epithelial cells

Answer 7

delamination

Question 8

grouping of mesenchymal cells

Answer 8

mesenchymal aggregation

Question 9

focal thickening of surface ectoderm

Answer 9

placode formation

Question 10

infolding or depression of epithelium to form a pit or groove

Answer 10

invagination

Question 11

separation of an invaginated epithelium from the original epithelium.

Answer 11

vesicle formation

Question 12

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

Answer 12

budding and branching

Question 13

outward folding or outpocketing of the epithelium

Answer 13

evagination

Question 14

programmed degeneration and eventual death of cells in area called necrotic zones.

Answer 14

normal cell death or apoptosis

Question 15

is the establishment of invisible blue print of cell subpopulations that serves as a guide in the formation of a particular tissue or organ.

Answer 15

Patterning or Pattern Formation

Question 16

mesenchymal aggregation and placode formation

Answer 16

visible signs

Question 17

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

Answer 17

cytodifferentiation

Question 18

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

Answer 18

tissue Interaction/tissue induction

Question 19

a fundamental inductive event, takes place during gastrulation

Answer 19

primary induction

Question 20

subsequent inductive events

Answer 20

secondary inductions

Question 21

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

Answer 21

inductive tissue Interaction

Question 22

a time during which organ systems in the body is being formed and obligatory inductive tissue Interaction morphogenesis are occurring.

Answer 22

Critical Period

Question 23

abnormalities present at birth that result from errors arising during development

Answer 23

congenital malformation or congenital defects

Question 24

role of heredity in embryonic development is very important, it is the genetic features of the parents that determine the appearance of the offspring.

Answer 24

hereditary/genetic factors

Question 25

also affect embryonic development by inducing birth defects that may produce monsters.

Answer 25

environmental or extrinsic factors