2nd ppt specifying

Question 1

Development of organism begins after fertilization

Single celled zygote becomes multicellular by ______

Answer 1

Mitosis

Question 2

_____

Developing cells acquire different ____ depending on their relative _____ within the embryo

Answer 2

Patterning

Identities
spatial positions

Question 3

_____

ensures that tissues and organs develop in the correct place and orientation

Answer 3

Pattern Formation

Question 4

Four processes of Development:

_____ sets the fate of the cell. restricts developmental fate

_____ cell ceases to divide, and develops specialized structural elements and distinct functional properties

_____ is the organization and spatial distribution of already differentiated cells

_____ increase in body size by cell division and expansion

Answer 4

Commitment

Differentiation

Morphogenesis

Growth

Question 4

Stages of Commitment:

1._____

The fate of a cell or tissue is said to be _____ when it is capable of ____ when placed into a neutral environment

At this stage, commitment is ____

Answer 4

Specification

Specified
Differentiating autonomously

Labile reversible

Question 5

Stages of Commitment:

2._____

A cell is said to be _____ when it is capable of _____ when placed into another region of cells different to it

At this stage, commitment is ____

Answer 5

Determination

Determined
Differentiating autonomously

Irreversible

Question 6

Order of development of an undifferentiated cell during embryogenesis (3)

Answer 6

Specification

Determination

Differentiation

Question 7

Modes of specification ( the ways commitment of cell can take place) (3)

Answer 7

Autonomous spefification

Conditional Specification

Syncytial Specification

Question 8

Modes of Specification:

_____
Very early on, it “knows” what it is without interacting with other cells

Here, the blastomeres of the early embryo are apportioned a set of critical ____ within the egg cytoplasm.

______

maternal substances in the egg that influence early development. This also leads to different gene expression

Answer 8

Autonomous Specification
Determination factors

Cytoplasmic/Morphogenetic determinants

Question 9

True or false, in autonomous specification, substances are distributed evenly in the unfertilized egg:

Answer 9

FALSE. it is distributed unevenly

Question 10

Modes of Specification (Autonomous specification):

_____
cell that turns into the flagellated part of the snail patella

Answer 10

Trochoblast

Question 11

Modes of Specification (Autonomous specification):

Characteristic of most _____

____ produce the same lineages in each embryo of thee species

Produces ____/____ development, cells cannot change fate if blastomere is lost

Answer 11

Invertebrates

Invariant cleavages

Mosaic/Determinative

Question 12

Modes of Specification (Autonomous specification):

The association of _____ with autonomous specification was confirmed by _____

_____ provided biochemical confirmation of cytoplasmic segragation of tissue determinants in early tunicate embryos

Answer 12

Conklin’s fate map
Cell-removal experiments

J.R. Whittaker

Question 13

Modes of Specification (Autonomous specification):

_____
muscle-specific transcription factors that give rise to muscle cells

Answer 13

Macho

Question 14

Modes of Specification :

_____
The process where cells achieve their respective fates by interacting with other cells

For example _____ (separated but using soluble growth factor) and _____ (attached)

Answer 14

Conditional Specification

Paracrine
Juxtacrine

Question 15

Modes of Specification (Conditional specification):

Factors that determine fate (3)

Answer 15

Cell-to-cell contacts

Secreted signals

Physical properties of local environment (mechanical stress)

Question 15

Modes of Specification :

_____
A cytoplasm that contains many nuclei is called a ____. Specification of cells within it is this type of specification.

Usually occurs in insects, involves the action of ____. They influence nuclei in ____ manner.

Answer 15

Syncytial Specification
Syncytium

Morphogen gradients
Concentration-dependent

Question 16

Morphogens involved in the Syncytial Specification of Drosophila Embryo:

The _____ (front) produces the ____ morphogen that is highest in concentration there

The _____ (back) produces the _____ and (_____) moprhogen that is highest in concentration there

They’re both transcription factors so different ratios activate different sets of genes

Answer 16

Anterior
Bicoid

Posterior
Caudal (and Nanos)

Question 17

Parts produced in the morphogen gradients (4

_____ high bicoid low caudal and nanos

_____ less bicoid small amount caudal and nanos

_____ low bicoid high caudal and nanos

Answer 17

Head
Thorax
Abdomen
Tail