L2

Question 1

cleavage

Answer 1

rapid division of cells

Question 2

of cells in cleavage increase ____ and in a ___ fashion

Answer 2

rapidly
logarithmic

Question 3

properties of cleavage (5)

Answer 3

splits the single cell of the fertilized egg into 100s of cells
usually synchronous
leads to cells of reduced size as growth does not occur
modified cell cycle allows quick cell divisions
dependent upon proteins and mRNAs stored in fertilized egg

Question 4

in a modified cell cycle (in drosophila), how is it modified?

Answer 4

only mitosis + s phase - no transcription, no RNA polymerase - only DNA polymerase

Question 5

what species has the following cleavage patterns?
radial
discoidal
bilateral
superficial
spiral
rotational

Answer 5

amphibians
fish + birds
sea squirts + tunicate
drosophila
snail
mammals + C. elegans

Question 6

cleavage pattern is determined by what

Answer 6

yolk thickness

Question 7

what is the direction of snails a classic example of?

Answer 7

maternal effect

Question 8

compaction

Answer 8

different cells become hard to distinguish bc of strong cell adhesion

Question 9

_____ is a protein that is really important for division

Answer 9

string

Question 10

CDK1 is present throughout the cell cycle, but is only active during what transition

Answer 10

G2 –> M

Question 11

_____ accumulates in late G2
controlled by the phosphorylation of other proteins

Answer 11

cyclin B

Question 12

____ removes the inhibitory phosphate on Tyr-15 activating ___ during mitosis

Answer 12

Cdc25
CDK1

Question 13

string is the drosophila homolog of ___

Answer 13

Cdc25

Question 14

CDK1 phosphorylates what three thins

Answer 14

histone 1
MAP
Lamin

Question 15

histone 1 does what

Answer 15

chromosome condensation

Question 16

MAP does what

Answer 16

spindle formation
causes microtubules to become dynamic

Question 17

lamin does what

Answer 17

nuclear envelope breakdown

Question 18

zygotic expression is initiated at the _____ transition by the changing ratio of ___ to ____

Answer 18

midblastula
nuclei
cytoplasm

Question 19

in cell division after cleavage, what are some properties ? (4)

Answer 19

not synchronous
occurs in specific regions which are associated with organ formation
G1 and G2 phases are introduced into the cell cycle
dependent upon zygotic transcription

Question 20

what are the different cleavage patterns?

Answer 20

radial
discoidal
bilateral
superficial
(spiral)
(rotational)

Question 21

_____ phosphorylates CDK1 on ______ to prevent activation during G2

Answer 21

Wee1
Try-15

Question 22

_____ removes the inhibitory phosphate on Try-15 activating CDK1 during mitosis

Answer 22

Cdc25

Question 23

string is drosophila’s homologue of what?

Answer 23

cdc25

Question 24

without cdc25, you would never enter ____ again

Answer 24

mitosis

Question 25

spindle causes _______ to become dynamic

Answer 25

microtubules

Question 26

zygotic expression is initiated at the _______ by changing the ratio of ____ to _____

Answer 26

midblastula transition

nuclei
cytoplasm