6.3 Meiosis

Question 1

Diploid

Answer 1

Cell owning 2 chromosomes of each type, one inherited from each parent

Question 2

Gamete

Answer 2

Sex cell

Question 3

Zygote

Answer 3

Fertilised egg

Question 4

Meiosis

Answer 4

Form of cell division resulting in the creation of gametes

Question 5

Haploid

Answer 5

Gamete containing half of the chromosome number of the parent cell

Question 6

Reduction division

Answer 6

First division in meiosis in which the number of chromosomes is reduced to half the original number

Question 7

Homologous chromosome

Answer 7

Nucleus containing matching sets of chromosomes

Question 8

Allele

Answer 8

Different versions of the same gene

Question 9

Locus

Answer 9

Position of gene on a region of a chromosome

Question 10

Meiosis 1

Answer 10

First division, pairs of homologous chromosomes separated into two cells. Each intermediate cell will only contain one full set of genes instead of 2, so the genes are haploid

Question 11

Meiosis 2

Answer 11

Second division is similar to mitosis. Pairs of chromatids present in each daughter cell are separated, forming 2 more cells. 4 haploid daughter cells are produced in total.

Question 12

Prophase 1

Answer 12

Chromosomes condense, nuclear envelope disintegrates, nucleolus disappears and spindle formation begins. Difference being homologous chromosomes pair up forming bivalents. Crossing over occurs

Question 13

Metaphase 1

Answer 13

Same as mitotic metaphase except homologous pairs of chromosomes assemble along metaphase plate instead of individual chromosomes. Orientation of pairs is random. Independent assortment occurs.

Question 14

Anaphase 1

Answer 14

Chromosomes pulled to opposite poles and chromatids stay joined. DNA sectioned that became entangled now break off and rejoin. Sister chromatids no longer identical

Question 15

Chiasmata

Answer 15

Point in anaphase 1 where chromatids break and rejoin

Question 16

Recombinant chromatids

Answer 16

Occurs when chromatids break and rejoin to chiasmata

Question 17

Telophase 1

Answer 17

Chromosomes assemble at each pole. Nuclear membrane reforms chromosomes uncoil. Undergoes cytokinesis

Question 18

Prophase 2

Answer 18

Chromosomes condense and become visible again. Nuclear envelope disintegrates and spindle formation begins

Question 19

Metaphase 2

Answer 19

Individual chromosomes assemble on metaphase plate. Chromatids no longer identical. Independent assortment occurs again

Question 20

Anaphase 2

Answer 20

Results in chromatids of individual chromosomes being pulled to opposite poles after division of centromeres, the same as in anaphase of mitosis.

Question 21

Telophase 2

Answer 21

Chromatids assemble at poles. Chromosomes uncoil and form chromatin again. Nuclear envelope reforms. Nucleolus becomes visible.