9.2: Meiosis And Genetic Variation

Question 1

Meiosis

Answer 1

Usually produces four daughter cells each with half the number of chromosomes as the parent cell.

Question 2

Diploid number

Answer 2

Full set of chromosomes

In humans: 23 pairs/46 individual

Question 3

Gamete

Answer 3

Sex cell

Question 4

Haploid number

Answer 4

One chromosome from each pair from each parent.

Half diploid number

Question 5

Two nuclear divisions in the process of meiosis

Answer 5

Meiosis 1

Meiosis 2

Question 6

Meiosis 1

Answer 6

Homologous chromosomes pair their chromatids wrap around each other.
Crossing over occurs.
One chromosome from each pair goes into one of the two daughter cells.

Question 7

Meiosis 2

Answer 7

The chromatids move apart into 4 daughter cells.

Question 8

Meiosis bring about genetic variation in 2 ways?

Answer 8

• independent segregation of homologous chromosomes

* new combinations of maternal and paternal alleles by crossing over

Question 9

Crossing over

Answer 9

Equivalent portions of chromatids exchanged.

Question 10

Gene

Answer 10

Length of DNA that codes for a polypeptide

Question 11

Locus

Answer 11

The position of a gene on a chromosome or DNA molecule

Question 12

Allele

Answer 12

One of the different forms of a particular gene.

Question 13

Homologous chromosomes

Answer 13

A pair of chromosomes, one maternal, one paternal, that have the same gene loci.

Question 14

Independent segregation

Answer 14

Random which chromosome from each pair ends up in which daughter cell.