Topic 7

Question 1

Why do cells divide?

Answer 1

1. Reproduction
2. Growth
3. Repair

Question 2

Genome

Answer 2

Complete set of genetic info

Question 3

How is DNA packed in prokaryotes?

Answer 3

Single, circular structure (plasmid)

Question 4

How is DNA packaged in eukaryotes?

Answer 4

Multiple, linear structure (chromosomes)

Question 5

Binary Fission

Answer 5

Prokaryotic method of production 2 daughter cells from 1 partner cell

Question 6

His tone

Answer 6

Bind to DNA to help give it shape

Question 7

Nucleosomes

Answer 7

DNA complexed with histones

Question 8

4 Levels of DNA packaging

Answer 8

1. Nucleosome
2. Solenoid fibre
3. Chromatin
4. Chromosome

Question 9

Telomere

Answer 9

The ends of the each sister chromatid

Question 10

Short arm

Answer 10

The shorter portion of the chromosome

Question 11

Long arm

Answer 11

The longer portion of the chromosome

Question 12

Centormere

Answer 12

Where the sister chromatids attach

Question 13

Kinetochoee

Answer 13

What the spindle fibres attach to on the sister chromatid

Question 14

How many chromosomes do humans have?

Answer 14

46 chromosomes

Question 15

How many pairs of chromosomes do humans have?

Answer 15

23 pairs

Question 16

Autosomes

Answer 16

Non sex chromosomes

Question 17

Sex chromosomes

Answer 17

The X and Y chromosomes

Question 18

How many autosomal pairs in humans?

Answer 18

22 pairs

Question 19

How many pairs of sex chromosomes in humans?

Answer 19

1 pair (XX or XY)

Question 20

What is the cause for Down syndrome?

Answer 20

An extra chromosome at pair 21 (trisomy 21)

Question 21

Stages of Interphase

Answer 21

1. G1 Phase (G0 Phase)
2. S Phase
3. G2 Phase

Question 22

G1 Phase

Answer 22

Cell carries out function and may grow

Question 23

S Phase

Answer 23

DNA replication and chromosomes duplicate

Question 24

G2 Phase

Answer 24

Cell grows and prepares for M phase (mitosis)

Question 25

Stages of Mitosis

Answer 25

1. Prophase 2. Prometaphase 3. Metaphase 4. Anaphase 5. Telophase 6. Cytokinesis

Question 26

What happens in Prophase?

Answer 26

1. Chromosomes condense 2. Nucleolus disappears 3. Mitotic spindles form to push the duplicated centromeres away

Question 27

What happens in Prometaphase?

Answer 27

1. Nuclear envelope breaks down 2. Mircotubles from opposite spindle poles attach to the 2 kinetochores

Question 28

What happens in Metatphase?

Answer 28

1. Chromosomes align at spindle midline / plate by the spindle fibres

Question 29

What happens in Anaphase?

Answer 29

1. Spindle separates sister Croatia’s and move them to spindle poles

Question 30

What happens in Telophase?

Answer 30

1. Chromosomes are decongested (return to chromatin) 2. Nuclear envelope reforms around chromosomes

Question 31

What happens in Cytokinesis?

Answer 31

1. Division of cytoplasm completes cell division

Question 32

What is the product of Mitosis?

Answer 32

2 genetically identical daughter cells

Question 33

Microtubule Pulling Force

Answer 33

Forces generated by micro tuble pulling an spindle pole separation are responsible for chromosome segregation

Question 34

Furrowing Ingression

Answer 34

Band of micro filaments forms just inside the plasma membrane forming a belt shaped ring (cytokinesis in animal cells)

Question 35

Cytokinesis in plant cells

Answer 35

Cell wall forms at the former spindle midpoint separating the new daughter cells

Question 36

Why internal checkpoints to the cell cycle?

Answer 36

Ensures that the reactions of one stage are complete before the other sage starts

Question 37

How is the cell cycle regulated?

Answer 37

Cyclin and CDKs

Question 38

What is a CDK and how is it activated?

Answer 38

A protein kinases witch phosphorylates and regulated activity of target proteins Activated with combined with cycling

Question 39

Different combinations of cyclin and CDKs do what?

Answer 39

Regulate different cycle transitions at different check points

Question 40

Control of cell division is lost

Answer 40

Cancer

Question 41

Metastases

Answer 41

When cancer cells break loose from the original tumour forming additional tumours around the body