1.5 a) The Cytoskeleton and the Cell Cycle

Question 1

The eukaryotic cell has a network of ___ ___ extending throughout the ___, called the cytoskeleton.

Answer 1

protein filaments, cytoplasm

Question 2

What two things does the cytoskeleton provide to cells?

Answer 2

mechanical support and shape

Question 3

The cytoskeleton consists of different protein structures such as ___, which are found in ___ cells.

Answer 3

microtubules, eukaryotic

Question 4

Microtubules are ___ and comprised of a protein called ___.

Answer 4

hollow, tubulin

Question 5

Microtubules radiate out of the ___ ___ ___ (___), aka the ___.

Answer 5

microtubule organising centre (MTOC), centrosome

Question 6

Name two things that microtubules control the movement of.

Answer 6

chromosomes, membrane-bound organelles

Question 7

Cell division requires ___ of the cytoskeleton.

Answer 7

remodelling

Question 8

What do microtubules form that plays a key role in cell division?

Answer 8

spindle fibres!

Question 9

Microtubules are ___ of tubulin.

Answer 9

polymers

Question 10

The formation of microtubules involves ____ of tubulin.
The breakdown/shortening of microtubules involves ___ of tubulin.

Answer 10

polymerisation, depolymerisation

Question 11

The cell cycle is divided into which two sections?

Answer 11

Interphase, the Mitotic Phase

Question 12

Which steps is the Interphase divided into?

Answer 12

G1, S and G2

Question 13

Which steps is the Mitotic Phase divided into?

Answer 13

Mitosis and Cytokinesis

Mitosis is divided into PMAT. (Prophase, Metaphase, Anaphase, Telophase.)

Question 14

What happens in G1?

Answer 14

G1 is the first growth phase where proteins and organelles are synthesized

Question 15

What happens in the S phase?

Answer 15

In the S phase, the cell continues to grow and copies its chromosomes in preparation for mitosis through DNA replication

Question 16

What happens in G2?

Answer 16

G2 is another growth phase

Question 17

Mitosis is the separation of ___ ___ by the ___ ___.

Answer 17

sister chromatids, spindle fibres (spindle microtubules)

Question 18

(1/4)
Name the three things that happen in the Prophase of Mitosis.

Answer 18

Chromosomes condense,
Nuclear membrane breaks down,
Spindle microtubules extend from the centrosome and attach to chromosomes via their kinetochores (at the centromere)

Question 19

(2/4)
What happens in the Metaphase of Mitosis?

Answer 19

Chromosomes line up along the metaphase plate (aka the equator of the spindle)

Question 20

(3/4)
What happens in the Anaphase of Mitosis?

Answer 20

Spindle microtubules shorten by depolymerisation, pulling the sister chromatids apart to opposite poles of the cell (once separated, chromatids become chromosomes)

Question 21

(4/4)
What happens in the Telophase of Mitosis?

Answer 21

Chromosomes decondense,
new nuclear membranes form around the chromosomes

Question 22

Cytokinesis is the ___ of the ___ into two ___ ___.

Answer 22

division, cytoplasm, daughter cells

Question 23

At the start of Meiosis, and Mitosis (prophase), the chromosomes ___.

Answer 23

condense.
(they decondense in the telophase)