Meiosis

Question 1

A chromosome consists of ___ coiled around ______.

Answer 1

DNA; histones (proteins)

Question 2

What is the chromatin network?

Answer 2

The thread-like network which DNA forms when the cell is not dividing.

Question 3

What is a somatic cell?

Answer 3

A body cell. i.e. snot a sex cell (gamete)

Question 4

What is a homologous chromosome pair?

Answer 4

A pair of chromosomes, one maternal and one paternal, which are similar to each other in size and shape and the type of genetic information they carry.

Question 5

How many sets of chromosomes do gametes have? And does this make them diploid or haploid?

Answer 5

One set; haploid

Question 6

Is the zygote haploid or diploid?

Answer 6

Diploid

Question 7

Does the zygote divide by mitosis or meiosis?

Answer 7

Mitosis

Question 8

What is a karyotype?

Answer 8

The complete set of chromosomes, arranged by size, shape and number in homologous pairs, within a somatic cell.

Question 9

What are autosomes?

Answer 9

Ordinary chromosomes that have nothing to do with determining sex.

Question 10

What are gonosomes?

Answer 10

The pair of sex chromosomes.

Question 11

How many pairs of autosomes does a human karyotype have?

Answer 11

22 pairs.

Question 12

Which pair of chromosomes are the gonosomes?

Answer 12

Pair number 23

Question 13

What is the cell cycle?

Answer 13

The period during which a cell grows, replicates genetic material and divides.

Question 14

What are the two parts of the cell cycle?

Answer 14

Interphase and Dividing phase.

Question 15

What are the two types of cell division?

Answer 15

Mitosis and meiosis.

Question 16

Which type of cells undergo mitosis?

Answer 16

Somatic cells.

Question 17

What are the phases of mitosis?

Answer 17

Prophase
Metaphase
Anaphase
Telophase

Question 18

Where does meiosis occur?

Answer 18

In the primary reproductive organs

Question 19

What occurs during prophase 1?

Answer 19

Nuclear membrane starts to disappear
Centrosome splits into centrioles which separate and form spindle fibres
Bivalent is formed as chromosomes form
Crossing over

Question 20

What is the chiasma (/chiasmata)?

Answer 20

The point at which the inner chromatids of a homologous pair touch

Question 21

What occurs during metaphase 1?

Answer 21

Chromosomes align at equator with homologous chromosomes on opposite sides
Chromosomes become attached to spindle fibres

Question 22

What occurs during anaphase 1?

Answer 22

One whole chromosome from each pair is pulled to opposite poles by the spindle fibres

Question 23

What occurs during telophase 1?

Answer 23

A new nuclear membrane forms around the groups of chromosomes at the poles
Nuclear membrane returns
Cytokinesis splits mother cell

Question 24

What occurs during prophase 2?

Answer 24

Nuclear membrane and nucleolus start to disappear

Centrosome splits into centrioles which separate and form spindle fibres

Question 25

What occurs during metaphase 2?

Answer 25

Single chromosomes align with the centromere on the equator

Each chromosome attaches to a spindle fibre

Question 26

What occurs during anaphase 2?

Answer 26

Centromere splits and the two chromatids are pulled to opposite poles

Question 27

What occurs during telophase 2?

Answer 27

New nuclear membrane forms around the unreplicated chromosomes at each pole
Cytokinesis

Question 28

Define meiosis

Answer 28

The cell division that produces reproductive cells in sexually reproducing organisms