Cell Cycle 3

Question 1

What is condensin?

Answer 1

Dramatic compaction or chromosome condensation and resolution to create separate units is achieved by this

Condensins allow sister chromatids to separate during anaphase without breakage of sister chromatids

Question 2

What are the 3 types of microtubules?

Answer 2

Kinetochore, interpolar and astral

Question 3

Kinetochores

Answer 3

Attach each chromosome to spindle pole

Question 4

Interpolar

Answer 4

Hold two halves of spindle together

Question 5

Astral

Answer 5

Interact with centrosomes (cell cortex)

Question 6

Dyneins

Answer 6

With regards to mitotic spindles, they move to the center of the cell. They are minus end directed microtubule motors. They pull spindle poles away from each other.

Question 7

Kinesins

Answer 7

Move to periphery of cells
They can walk towards plus ends of microtubules
Has 2 globular heads and elongated coil-coil tails
Plays important role in chromosome separation

Question 8

Kinesin-5

Answer 8

two motor domains that interact with plus end of anti-parallel microtubules. The two anti-parallel microtubules past each other to force or push the spindle poles/centromeres apart. Without Kinesin -5, spindle collapses therefore it is a crucial element.

This is the opposite of what Kinesin-14 does.

Question 9

Kinesin-14

Answer 9

Minus oriented directed motor with a single motor domain

Walks towards minus end to pull poles together

Opposite of Kinesin-5 which separates centrosomes.

Question 10

Kinesin-5 and Kinesin-14 counteract each other but without Kinesin-5 what happens?

Answer 10

spindle collapse

think of letting go rope during tug of war

Question 11

Kinesin-4,10

Answer 11

Aka Chromokinesins
These are plus directed motors
Movement is towards plus end
It pushes attached chromosomes away from the pole

Question 12

Cell division control is controlled in 3 ways

Answer 12

mitogens
Growth factors
Survival factors