Ch. 2

Question 1

_______: the generation of specialized cell types often involving dramatic changes in cell structure and function

Answer 1

Differentiation

Question 2

_______: A cell is _______ when it has the potential to differentiate autonomously when placed in a neutral environment

Answer 2

specification
specified

Question 3

_______: a cell is _______ when it is capable of differentiating autonomously, even when placed in another region of the embryo

Answer 3

determination
determined

Question 4

What is the difference between specification and determination

Answer 4

specification is still reversible while determination is fully committed

Question 5

What are the 3 different strategies of commitment?

Answer 5

1) autonomous specification
2) conditional specification
3) syncytial specification

Question 6

_______ specification is determined by inherited factors present in the oocyte

Answer 6

autonomous
- mosaic development, each “tile” receiving its instructions without cell-to-cell interactions

Question 7

In autonomous specification, molecules such as proteins or mRNA are called ________

Answer 7

morphogenic determinants
- unequally distributed and allows cells to “know” very early what they will become

Question 8

autonomous specification is commonly found in _______

Answer 8

invertebrates

Question 9

In autonomous specification, early cleavage patterns are _______

Answer 9

invariant (always the same)

Question 10

maybe a card on 8-cell tunicate embryo

Answer 10

macho tf ex of autonomous specification

Question 11

_______ specification is determined by a cell’s position in the embryo

Answer 11

conditional

Question 12

Conditional specification is common in ______ and some _______

Answer 12

vertebrates
some invertebrates

Question 13

Conditional specification typically involves large movements/rearrangement of cells ______ or _______ with specification

Answer 13

prior to or concomitant
(at the same time)

Question 14

What are the 3 ways conditional specification occurs through the interaction with other cells?

Answer 14

1) cell to cell contacts
2) secreted signals from neighbors
3) mechanical stresses and physical forces of environment

Question 15

In conditional specification, early cleavage patterns are _______

Answer 15

variable

Question 16

_______ remove the fertilization envelope and separate the four blastomeres

Answer 16

isolation experiments

Question 17

Describe combination of pathways for sea urchins
2 steps

Answer 17

1) micromeres develop autonomously into skeleton
2) micromeres secrete signals that induce conditional specification to cells around it

Question 18

Describe combination of pathways for frog embryos

Answer 18

1) cells opposite of sperm entry develop autonomously into head endoderm
2) produce paracrine signaling to conditionally specify cells around them to produce brain

Question 19

_______ specification through interactions of nuclei and TF’s within a common cytoplasm

Answer 19

syncytial

Question 20

Syncytial specification is common in ______

Answer 20

insects

Question 21

In syncytial specification, early cleavage patterns are _______

Answer 21

variable

Question 22

a large single cell with many nuclei is called a _______

Answer 22

syncytium

Question 23

_______ occurs in drosophila after the 13th nuclear division

Answer 23

cellularization
- formation of individual cell membranes

Question 24

Briefly describe syncytial specification

Answer 24

individual nuclei are positioned by microtubules along the anterior/posterior axis

Question 25

_______: TF and mRNA concentration highest at the anterior end

Answer 25

bicoid

Question 26

_______: TF and mRNA concentration highest at the posterior end

Answer 26

caudal