Genetic Information

Question 1

What is Mitosis for?

Answer 1

"Growth" and renewal/replacement of cells
Asexual reproduction (cells produced are genetically identical)

Question 2

What are the stages of Mitosis?

Answer 2

(I)PMAT

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Interphase
Prophase
Metaphase
Anaphase
Telophase
~~~

Question 3

Mitosis - Interphase

Answer 3

‘Resting phase’

DNA replication, protein synthesis and ATP synthesis take place

Question 4

Mitosis - Prophase

Answer 4

Chromosomes condense (shorten and thicken)
Any centrioles present move to poles
Spindle begins to form

Question 5

Mitosis - Metaphase

Answer 5

Spindle fibres extend to cover whole cell
Centromeres line up at equator of cell
Chromosomes arranged singly

Question 6

Mitosis - Anaphase

Answer 6

Chromosomes pulled apart by spindle fibres attaching onto centromeres
Chromosomes pulled to poles by centromeres contracting

Question 7

Mitosis - Telophase

Answer 7

Chromatids reach poles (now known as chromosomes)
Cell cytoplasm divides (cleavage furrow = animals, cell plate = plants)
Nuclear membrane reforms
Chromosomes indistinct

Question 8

What is cytokinesis?

Answer 8

After Telophase, cytoplasm splits

DNA content is halved

Question 9

What are cancers a result of?

Answer 9

Uncontrolled mitosis

Tumours = irregular mass of cells caused by mutations in genes in cell division

Question 10

What is Meiosis for?

Answer 10

Sexual reproduction (produces genetically different cells)

Question 12

What are the stages of Meiosis?

Answer 12

Meiosis 1:
(I)P1M1A1{T1}
Meiosis 2:
{P2}M2A2T2

*{P2} won’t happen unless {T1} occurs

Question 13

Meiosis - Interphase

Answer 13

DNA replication, protein synthesis and ATP synthesis take place

Question 14

Meiosis - Prophase 1

Answer 14

Chromosomes condense
Any centrioles present move to poles
Spindle begins to form
Chromosomes arranged in homologous pairs, these pairs overlap at chiasma

Question 15

Meiosis - Metaphase 1

Answer 15

Chromosomes line up at equator in homologous pairs

Maternal/paternal chromosomes align randomly on each side

Question 16

Meiosis - Anaphase 1

Answer 16

Chromosomes pair (bivalent) pulled apart by contracting spindle fibres
Chromosomes pulled to poles
Chiasma break, maternal and paternal chromosome sections pulled to opposite pole of chromosome to which they were joined (random assortment)

Question 17

Meiosis - Telophase 1

Answer 17

Nuclear membrane reforms
Chromosomes indistinct
Cell division/cytokinesis
In plants, cell plate forms new cell wall

Question 18

Meiosis - Prophase 2

Answer 18

Chromosomes condense
Spindle forms
Ends when nuclear membrane breaks down

*remember- 2 cells were formed end of Meiosis 1. Meiosis 2 is basically Meiosis 1 repeated!

Question 19

Meiosis - Metaphase 2

Answer 19

Chromosomes line up at equator, they are attached to spindle fibres by their centromeres

Question 20

Meiosis - Anaphase 2

Answer 20

Spindle fibres shorten separating the chromatids which pulls them to opposite poles of the cell

Question 21

Meiosis - Telophase 2

Answer 21

Nuclear membrane forms around each set of chromosomes
Chromosomes uncoil
Cytokinesis- cells split to form 4 daughter cells

Question 22

Number of divisions in Mitosis

Answer 22

1

IPMAT, cycle begins again!

Question 23

Number of divisions in Meiosis

Answer 23

2

Meiosis 1 & 2

Question 24

Number of cells produced in Mitosis

Answer 24

2

Question 25

Number of cells produced in Meiosis

Answer 25

4

Question 26

Ploidy of daughter cells in Mitosis

Answer 26

Diploid

same as original cell

Question 27

Ploidy of daughter cells in Meiosis

Answer 27

Haploid

Question 28

Variation in Mitosis

Answer 28

All genetically identical (no variation)

Question 29

Variation in Meiosis

Answer 29

All genetically different due to random assortment (variation)