Unit 1 - Protein Control of Cell Division

Question 1

What is the cytoskeleton?

Answer 1

A microscopic network of proteins and tubules in cytoplasm, that supports the shape and function of cells

Question 2

What are microtubules?

Answer 2

Microscopic hollow tubes made of tubulin that are part of cell’s cytoskeleton

Question 3

What is tubulin?

Answer 3

The protein that polymerises into long chains or filaments that form microtubules

Question 4

What is the microtubule organising centre?

Answer 4

The structure found in eukaryotic cells from which microtubules are produced for the formation of spindle fibres

Question 5

What are spindle fibres?

Answer 5

Microtubules to which the chromosomes are attached by kinetochores during cell division

Question 6

What is the cell cycle?

Answer 6

A 4 stage process in which the cell increases in size, copies its DNA, prepares to divide and divides by mitosis

Question 7

What is mitosis?

Answer 7

The division of the nucleus to form two nuclei, each with a full complement of chromosomes

Question 8

What is cytokinesis?

Answer 8

The division of cytoplasm to form two daughter cells

Question 9

What are kinetochores?

Answer 9

A complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach

Question 10

What is the centromere?

Answer 10

The specialised DNA sequence of a chromosome that links a pair of sister chromatids

Question 11

What are cyclin proteins?

Answer 11

Proteins that control the progression of cells through the cell cycle by activating cyclin-dependent kinase enzymes

Question 12

What do cyclin-dependent kinases cause?

Answer 12

The phosphorylation of proteins, which stimulates the cell cycle

Question 13

What is p53?

Answer 13

A tumour-suppressor protein that is dysfunctional in several major cancers

Question 14

What is retinoblastoma protein?

Answer 14

A tumour-suppressor protein that can stimulate DNA repair, arrest the cell cycle or cause cell death by activation of caspases

Question 15

What is proto-oncogene?

Answer 15

A normal gene, usually involved in the control of the cell growth or division, which can mutate to form a tumour-promoting oncogene

Question 16

What is tumour-promoting oncogene?

Answer 16

A mutated proto-oncogene that has the potential to cause cancer

Question 17

What is apoptosis?

Answer 17

Programmed cell death triggered by cell death signals that can be external or internal

Question 18

What are death signal molecules?

Answer 18

External or internal signals that result in the activation of protease enzymes called caspases, which cause apoptosis

Question 19

What are caspase cascades?

Answer 19

Protease enzymes involved in a series of reactions that destroy a cell

Question 20

What is metamorphosis?

Answer 20

The process that involves a significant change in an organism’s physical form during development

Question 21

What are growth factors?

Answer 21

A naturally occurring substance, usually a protein or steroid hormone, capable of stimulating cell growth

Question 22

What does the cytoskeleton consist of?

Answer 22

Different protein strctures including microtubules

Question 23

What are microtubules?

Answer 23

Hollow cylinders composed of tubulin.

Question 24

Where do microtubules radiate from?

Answer 24

MTOC ( Microtubule organising centre)

Question 25

What does the formation and breakdown of microtubule involve?

Answer 25

-Polymerisation of tubulin (growth of microtubule)
-Depolymerisation of tubulin (shrinkage of microtubule)

Question 26

What are the functions of the cytoskeleton?

Answer 26

• Gives mechanical support and shape to cells
• Microtubules control membrane-bound organelles and chromosomes
• Microtubules form spindle fibres that are active during cell division

Question 27

What is cell division required for?

Answer 27

Growth and repair

Question 28

What are the 2 parts of the cell cycle?

Answer 28

• Interphase
• Mitotic phase

Question 29

What phase lasts longer, Interphase or mitotic phase?

Answer 29

Interphase

Question 30

What are the 3 sub-phases of interphase?

Answer 30

• G1
• S phase
• G2

Question 31

What happens during G1 sub-phase?

Answer 31

Growth period where proteins and organelles are synthesised

Question 32

What happens during S phase?

Answer 32

Cell continues to grow, DNA is replicated in prep for mitosis

Question 33

What happens during G2 sub-phase?

Answer 33

Another growth period where proteins and organelles are synthesised?

Question 34

What are the 2 sub-phases of the mitotic phase?

Answer 34

• Mitosis
• Cytokinesis

Question 35

What happens during mitosis?

Answer 35

Chromosomal material is separated by spindle microtubules

Question 36

What happens during cytokinesis?

Answer 36

The cytoplasm separates into two daughter cells

Question 37

What are the 4 stages of mitosis?

Answer 37

• Propase
• Metaphase
• Anaphase
• Telophase

( Pass Me Another Tequila )

Question 38

What happens during prophase?

Answer 38

• DNA condenses into chromosomes, both have two sister chromatids.
• Nuclear membrane breaks down
• Spindle microtubules extend from MTOC by polymerisation and attach to chromosomes via kinetochores in centromeme

Question 39

What happens during metaphase?

Answer 39

• Chromosomes are aligned at the metaphase plate (equator of spindle)

Question 40

Wh