Chromosome and Organelle Movement

Question 1

How does dynein bind to organelles?

Answer 1

Binds indirectly via dynactin

Question 2

How does kinesis bind to organelles?

Answer 2

Binds to organelles directly

Question 3

What are the two major classes of microtubule-based motor proteins?

Answer 3

Dynein and kinesin

Question 4

Discuss the directionality of dynein and what function it serves

Answer 4

Dynein is minus-end directed (moves towards minus-end)

Involved in construction of microtubule spindle and positioning of centrosome and nucleus in cell migration

Question 5

Discuss the directionality of kinesin and what function it serves

Answer 5

Plus-end directed (moves towards plus-end)

Involved in mitotic spindle formation and chromosome segregation

Question 6

Anaphase: Does anaphase A or B occur first?

Answer 6

They occur simultaneously

Question 7

What occurs in anaphase A?

Answer 7

• Movement of chromosomes to poles

- Shortening of kinetochore microtubules

Question 8

What occurs in anaphase B?

Answer 8

• Movement of poles apart

- Lengthening and sliding of polar microtubules

Question 9

What 2 motor proteins does anaphase B depend on? What do they each do?

Answer 9

1. Kinesin - push the poles apart via Interpolar MTs

2. Dynein - pull the poles apart via Astral MTs