Meiosis

Question 0

Tetrad

Answer 0

Paired set of homologous chromosomes that can exchange pieces of genetic information with one another or “cross over”

Question 1

Karyotype

Answer 1

A display of all the chromosomes within a cell at the time of metaphase, arranged by matching pairs

Question 2

Recombinant

Answer 2

A chromosome that has gene combinations different from those carried by the parental chromosomes

Question 3

Describe diploid cells.

Answer 3

Diploid cells have two sets of chromosomes present (homologous pairs), and thus have 23 pairs of chromosomes (for a total of 46 chromosomes).

Question 4

Describe haploid cells.

Answer 4

Haploid cells have a single set of chromosomes present, and so have 23 chromosomes in the cell.

Question 5

Gametes

Answer 5

Sex cells - egg or sperm. They are haploid cells.

Question 6

Zygote

Answer 6

A zygote is what is created when haploid gametes merge during the process called fertilization. It is a diploid cell.

Question 7

Fertilization

Answer 7

The process through which haploid gametes merge into a zygote (a type of diploid cell).

Question 8

Meiosis

Answer 8

Meiosis is a type of cell division that produces four haploid daughter cells (gametes) each time it occurs in diploid organisms.

Question 9

What occurs in the interphase stage of meiosis?

Answer 9

In the interphase stage of meiosis, chromosomes duplicate, yielding sister chromatids, and centrosomes emerge.

Question 10

What occurs, broadly, in the meiosis I stage of meiosis?

Answer 10

Broadly, homologous chromosomes separate.

Question 11

What occurs, broadly, during the meiosis II stage of meiosis?

Answer 11

Broadly, sister chromatids separate during the meiosis II stage of meiosis.

Question 12

What occurs in the prophase I stage of meiosis?

Answer 12

During the prophase I stage of meiosis, homologous chromosomes pair up and exchange segments (mixing up the DNA).

Question 13

What occurs during the metaphase I stage of meiosis?

Answer 13

During the metaphase I stage of meiosis, the tetrads line up in the center of the cell.

Question 14

What occurs in the anaphase I stage of meiosis?

Answer 14

In the anaphase I stage of meiosis, the pairs of homologous chromosomes split up, but the sister chromatids remain attached.

Question 15

What occurs during the Telophase I and cytokinesis stages of meiosis?

Answer 15

During the telophase I and cytokinesis stages of meiosis, two haploid cells form, but the chromosomes are still double.

Question 16

How does genetic mixing-up occur in prophase I of meiosis?

Answer 16

In prophase I, genetics get mixed up because homologous chromosomes pair up and some crossing-over occurs between non-sister chromatids, resulting in recombinant chromatids.

Question 17

How does genetic mixing-up occur during the metaphase I stage of meiosis?

Answer 17

During the metaphase I stage of meiosis, genetic mixing-up occurs when the homologous pairs of chromosomes align independently.

Question 18

What occurs differently in the anaphase II stage of meiosis?

Answer 18

In the anaphase II stage of meiosis, sister chromatids separate.

Question 19

What occurs in the telophase II and cytokinesis stage of meiosis?

Answer 19

In the telophase II and cytokinesis stage of meiosis, the four haploid daughter cells form, containing single chromosomes.

Question 20

Nondisjunction

Answer 20

Nondisjunction is an error in meiosis when members of a chromosome pair fail to separate. It normally results in a non-viable offspring.

Question 21

Down Syndrome

Answer 21

A disability resulting from an error in meiosis, when a person has an extra #21 chromosome.