Lecture 5- Cell Cycle/Mitosis

Question 0

Hypoplasia

Answer 0

Growth of size of cells (not an increase in number of cells)

Question 1

Hyperplasia

Answer 1

Growth of the size of an organism by increasing the number of cells

Question 2

Centrosomal Cycle

Answer 2

Pair of centrioles orient themselves perpendicular to one another

Question 3

Nuclear Cycle

Answer 3

Lamins are phosphorylated to allow nuclear membrane to dissociate (after mitosis, lamins are dephosphorylated and membrane is reestablished)

Question 4

Cytoplasmic Cycle

Answer 4

Increase in volume of cytoplasm to a critical mass for mitosis to occur

Question 5

Chromosomal Cycle

Answer 5

Replication of DNA molecules in the form of chromosomes

Question 6

G-1 Phase of Mitosis

Answer 6

First gap/growth phase

[Cyclin E] increases and binds to Cdk2 kinase forming MPF

Question 7

S Phase of Mitosis

Answer 7

DNA synthesis occurs
E-cyclins degraded and inactive Cdk2 kinase
[A-cyclin] increases toward end of S phase

Question 8

MCM proteins

Answer 8

Helicase proteins necessary for DNA replication…bind to origin of replication

Question 9

G-2 Phase of Mitosis

Answer 9

Second gap/growth phase

Cyclin-A binds to Cdk1 which leads to activities necessary for mitosis

Question 10

M Phase of Mitosis

Answer 10

B-cyclin is degraded (MPF) toward end of phase
Cdk1 inactivated
Checkpoint for proper chromosomal alignment during metaphase

Question 11

MPF

Answer 11

Made up of Cyclin-B/Cdk1 complex

Dephosphorylation necessary to activate for entry into the M phase

Question 12

G-0 Phase of Mitosis

Answer 12

Condition of a cell that has been taken out of the classical cell cycle

Question 13

Embryonic Cells

Answer 13

Little time in G-1 phase

embryonic & some tumor cells

Question 14

Labile Cells

Answer 14

More time in G-1 phase and grow and become differentiated

epithelia of gut and epidermis, hematopoietic cells

Question 15

Non-dividing Cells

Answer 15

Permanently locked in G-1 phase and never divide

skeletal muscle, cardiac muscle, & neurons

Question 16

Karyokinesis

Answer 16

Physical division of nuclear material

Question 17

Cytokinesis

Answer 17

Physical division of cytoplasmic material

Question 18

Endomitosis

Answer 18

Occurs when karyokinesis is not followed by cytokinesis and results in an increase in ploidy

Question 19

What triggers cytokinesis?

Answer 19

Inactivation of Cdk1

Question 20

Rb Protein

Answer 20

Retinoblastoma…Involved in expression of genes required for cell cycle progression
Is product of tumor suppressor gene

Question 21

p53 Protein

Answer 21

Stops cell cycle at G-1 checkpoint