Meoisis

Question 1

Interphase

Answer 1

Interphase: The DNA is replicated during ‘S’ phase of interphase and other organelles are replicated during the growth phases of interphase

Question 2

Prophase 1

Answer 2

DNA condenses to become visible as chromosomes, the spindle is formed from centrioles at the poles of the cell and the nuclear envelope disintegrates. In late prophase chiasmata are formed, points where the DNA from non-sister chromatids crosses over, resulting in the exchange of genetic material.

Question 3

Metaphase 1

Answer 3

Homologous pairs of chromosomes line up along the equator of the cell

Question 4

Anaphase 1

Answer 4

Homologous pairs of chromosomes are separated and pulled to opposite poles of the cell and the spindle disintegrates.

Question 5

Telophase 1

Answer 5

New nuclear envelopes are formed and the chromosomes unravel to form chromatin

Question 6

Cytokinesis

Answer 6

The division of the cytoplasm to complete the formation of 2 cells from the first division of meiosis

Question 7

Prophase 2

Answer 7

DNA condenses once again to become visible as chromosomes, the spindle is formed from centrioles at the poles of the cell and the nuclear envelope disintegrates

Question 8

Metaphase 2

Answer 8

Chromosome existing as sister chromatids line up along the equator of the cell

Question 9

Anaphase 2

Answer 9

Sister chromatids are separated and pulled to opposite poles of the cell as the centromeres split. After the sister chromatids have been separated they can be referred to as chromosomes

Question 10

Telophase 2

Answer 10

New nuclear envelopes are formed and the chromosomes unravel to form chromatin.

Question 11

Cytokinesis

Answer 11

The division of the cytoplasm to complete the formation of 2 cells from the first division of meiosis

Question 12

What is formed

Answer 12

4n to 2n to n

1. 1 doubled genetic information (92)
2. 2 diploid cells (46)
3. 4 haploid cells (23)

four haploid daughter cells

Question 13

differences between mitosis and meiosis

Answer 13

Mitosis

• one cell division
• two cells produced
• forty six chromosomes produced
• used for cell division; repair of tissues, cell replacement
• used for the synthesis of new cells
• happens everywhere

Meiosis

• two cell divisions
• four cells produced
• twenty three chromosomes produced
• used for gamotegenisis
• happens in the sexual organs (testes and ovaries)

Question 14

variation

Answer 14

the random distribution of genes into gametes to produced varied possibilities of children and avoid cloning

Question 15

why can sex aces not divide by mitosis

Answer 15

they’re haploid

Question 16

what is meiosis

Answer 16

division of cells to produce sex cells

- reduction division

Question 17

what is random assortment

Answer 17

Random orientation (independent assortment) of the homologous pairs (the way they face) can occur;
each pair may orient with its maternal or paternal homolog closer to a given pole

Question 18

what is crossing over

Answer 18

-DNA on non-sister chromatids breaks at corresponding point(s) along their length;
• DNA on non-sister chromatids reattaches;
• As a result, genes (alleles) are swapped between non- sister chromatids

Recombination:
the re-assortment of genes into new combinations (different from those of the parents)