Mitosis & Cell division

Question 1

What are the stages in the cell cycle?

Answer 1

interphase
nuclear division (mitosis)
cell division (cytokinesis)

Question 2

What are the three stages of interphase called?

Answer 2

G1 - gap stage 1, S - synthesis stage, G2 - gap stage 2

Question 3

What happens in G1?

Answer 3

Cell grows and receives signal to divide
(cell membranes and organelles are doubled)

Question 4

What happens in S?

Answer 4

synthesis of new DNA in semi-conservative replication (identical)

Question 5

What happens in G2?

Answer 5

more growth, protein synthesis, error checking of DNA

Question 6

What happens in mitosis?

Answer 6

M stage, cell growth stops

Question 7

What is cytokinesis?

Answer 7

where the cell splits into two, cytoplasm and cell membrane splits, identical daughter cells

Question 8

What is mitosis?

Answer 8

Where two identical nuclei are produced

Question 9

What are the functions of mitosis?

Answer 9

1. growth of tissue
2. replacement of damaged tissue
3. asexual reproduction

Question 10

What are the stages of mitosis?

Answer 10

Prophase, metaphase, anaphase, telophase

Question 11

What happens in the prophase?

Answer 11

• chromosomes condenses (visible)
• chromosomes made from: 2x identical chromatids, joined w/centromere
• centromeres move to opposite poles
• spindle fibres emerge from centrosomes
• nuclear envelope breaks down

Question 12

What happens in the metaphase?

Answer 12

• chromosomes reach opposite ends of cell
• spindle fibres extend from centrosomes
• chromosomes line up in the middle of the cell
• spindle fibres attach to centromeres

Question 13

What happens in the anaphase?

Answer 13

• chromatids separate at centromeres
• spindle fibres shorten
• chromosomes pulled by spindle fibres

Question 14

What happens in the telophase?

Answer 14

• chromosomes arrive (at poles) and decondense
• nuclear envelope reforms
• spindle fibres break down

Question 15

What is a chromatid?

Answer 15

the two identical halves of the chromosome

Question 16

What is the centromere?

Answer 16

Where the chromatids are joined together

Question 17

What is the centrosome?

Answer 17

the organelle where spindle fibres come from

Question 18

What is mitotic index?

Answer 18

(number of cells with visible chromosomes / total number of cells) x 100

Question 19

What happens in cytokinesis?

Answer 19

cytoplasm divides forming two genetically identical cells (after the telophase of mitosis)

Question 20

What is a cleavage furrow?

Answer 20

dip between two cells when they are dividing

Question 21

What is the plant version of a cleavage furrow?

Answer 21

cell plate

Question 22

how do you recognise prophase?

Answer 22

• chromosomes are visible
• nuclear envelope breaks down

Question 23

how do you recognise metaphase?

Answer 23

• chromosomes are lined up in the middle of the cell

Question 24

How do you recognise anaphase?

Answer 24

• chromosomes are moving away from middle of cell (to opposite poles)

Question 25

how do you recognise telophase?

Answer 25

- chromosomes are at opposite poles - chromosomes decondense - nuclear envelope reforms

Question 26

What does benign mean?

Answer 26

non cancerous, stays in one place

Question 27

What does malignant mean?

Answer 27

cancer that moves through the blood to other parts of the body

Question 28

What is metastasis?

Answer 28

where malignant tumours spread through the body

Question 29

what type of tumors does metastasis form?

Answer 29

secondary tumors

Question 30

what are oncogenes?

Answer 30

genes that stimulate uncontrolled cell division

Question 31

What does methotrexate do? (cancer)

Answer 31

inhibits the synthesis of DNA nucleotides in cells

Question 32

What does Vincristine and taxol do? (cancer)

Answer 32

prevent the formation of the mitotic spindle