Unit 7

Question 1

G1 phase

Answer 1

Major period of cell growth where duplication of organelles and volume of cytoplasm is increased

Question 2

After G1 phase cells can do 2 things

Answer 2

Enter s phase, or entered g0

Question 3

S phase

Answer 3

DNA replication occurs, s cyclin and cdks are active

Question 4

G2 phase

Answer 4

Cell size doubles in prep for mitosis and s cyclin and cdks are active

Question 5

G2 /m checkpoint

Answer 5

Commitment to divide that is managed by m cdks

Question 6

Fate of m cdk and m cyclins during mitosis

Answer 6

Active during first half, and the targeted for destruction during anaphase by the anaphase promoting complex (apc)

Question 7

G0

Answer 7

Referred to as post mitosis state where cells can be in temporary arrest called quiescent, or permanent arrest - senescent

Question 8

What cells typically remain in g0 for a long time

Answer 8

Neurons, cardiac muscle, rbc

Question 9

Examples of quiescent cells in g0

Answer 9

Liver cells, lymphocytes, stem cells

Question 10

FACS

Answer 10

Fluorescence activated cell sorting

Question 11

Number of chromosomes remains the same in a facs peak one and two

Answer 11

True

Question 12

Discrete process of cell cycle

Answer 12

Events that only occur at certain points, like replication and mitosis

Question 13

Continuous processes in cell cycle

Answer 13

Occur through cycle, like nutrient assimilation and cell growth

Question 14

MPF

Answer 14

Maturation promoting factor

Question 15

Something In cytoplasm controls entry into mitosis

Answer 15

MPF

Question 16

Cdk stands for

Answer 16

Cyclin dependent kinase

Question 17

Active m cdk is also known as

Answer 17

MPF

Question 18

A kinase is an enzyme that

Answer 18

Phosphorylates target proteins using bound atp

Question 19

Phosphorylation by kinases results in a

Answer 19

Conformational change that can either activate or inactivate target

Question 20

Activity of cyclin during cell phase

Answer 20

Accumulates during interphase, reaching a max in mitosis, the rapidly declines at end of mitosis

Question 21

Proteins that are phosphorylated by m cdks

Answer 21

Histone h1, and condensins
Nuclear lamins
Nucleolin
Srk
Cdc 25
Anaphase promoting complex

Question 22

Cdk binding to cyclin is ___ but not ____ for enzyme activity

Answer 22

Necessary but not sufficient

Question 23

CDK turing on via

Answer 23

1. Association with cyclin
2. Phosphorylation and dephosphorylation of cyclin complex

Question 24

Once cyclin is bound to cdk phosphates are added and removed based on

Answer 24

Current cellular conditions

Question 25

Growth inhibitor signal for g2 m checkpoint

Answer 25

Blocking activation of cyclin /cdk

Question 26

What happens if there is indestructible m cyclin

Answer 26

Cells get stuck in mitosis as degradation can’t happen and MPF stays active, no reset to g1

Question 28

What helps further packing of interphase chromatin fiber

Answer 28

Condensins

Question 29

What helps hold sister chromatids together

Answer 29

Cohesins

Question 30

Structural definition of condensins

Answer 30

Highly processive motors that help to loop dna

Question 31

What phase do the nucleoli disappear

Answer 31

Prophase

Question 32

Prometaphase starts

Answer 32

With breakdown of the nuclear envelope so chromosomes can attach to spindle

Question 33

How do chromosomes attach to spindle

Answer 33

Kinetochores

Question 34

What triggers phosphorylation of nuclear lamins

Answer 34

Activated m cdk

Question 35

Three classes of mt making up the mitotic spindle

Answer 35

Astral, kinetochore, interpolar

Question 36

Interpolar mt function

Answer 36

Stabilize spindle and push poles apart, interact via motor proteins

Question 37

Astral mt function

Answer 37

Anchors and positions spindle with help of Dynein motors at cortex

Question 38

Kinetochore attachment is referred to as happening via

Answer 38

Random growth and shrinkage of mt

Question 39

What makes a kinetochore stable

Answer 39

High tension, attached to sister chromatid from each pole

Question 40

Mt are shorter and more dynamic in mitotic cells than in interphase cells because

Answer 40

Increased activity of mt depolymerizing proteins to help proper spindle assembly

Question 41

What is poleward flux

Answer 41

Tubulin is continually added at the plus ends and lost at minus ends so the mt stays the same length as gfp labeled tubulin moves towards pole

Question 42

Anaphase a

Answer 42

Sister chromatids pulled towards opposite spindle poles and kinetochore mt shortens at plus end. Dynein helps pull chromatids to poles

Question 43

Anaphase B

Answer 43

Spindle poles themselves move farther apart. Kinesin pushes interpolar mt apart by walking towards plus end

Question 44

Taxol affects on anaphase a and B

Answer 44

Taxol stabilizes mt. Anaphase a is affected since kinetochore mts cannot depolymerize but in B, interpolar mt can still lengthen

Question 45

APC inhibition results in

Answer 45

Metaphase arrest

Question 46

Non degradable m cyclin results in

Answer 46

Anaphase arrest

Question 47

Telophase is controlled by destruction of

Answer 47

M cyclin

Question 48

How is m cyclin degraded

Answer 48

Will be tagged with ubiquitin and destined for proteome

Question 49

How does nuclear envelope reassemble

Answer 49

Lamins become dephosphorylated and and membranes fuse together by nuclear pores associating with one another

Question 50

What is the difference in cytokinesis in plant cells

Answer 50

Golgi derived vesicles will come together and form a phramogmoplast which develops into a cell plate to form a new cell wall

Question 51

Cytochlasins effect on mitosis

Answer 51

Bind to plus end of actin filaments and prevent polymerization so cell movement and cytokenisis fail to separate cells

Question 53

Effect of colchicine on anaphase a and B

Answer 53

A none, as mt is depolymerizing. In B as mt are polymerizing the spindle poles cannot separate as interpolar mt will not form and function correctly