1.6 cell division

Question 1

Binary fission

Answer 1

A type of asexual reproduction common among prokaryotes where one cell divides giving rise to two cells, each having the potential to grow to the size of the original cell [this is not mitosis].

Question 2

Mitosis

Answer 2

The division of the nucleus into two genetically identical daughter nuclei.

Question 3

Interphase

Answer 3

A very active phase of the cell cycle, when the cell is not in mitosis.

Question 4

The cell cycle

Answer 4

The sequence of events between one cell division and the next.

Question 5

Centriole

Answer 5

A self-replicating cylindrical organelle, found in pairs that is involved in the process of nuclear division.

Question 6

Centromere

Answer 6

The region joining the two sister chromatids where it becomes attached to a microtubule during mitosis.

Question 7

Chromosome

Answer 7

A strand of DNA that carries the genetic information.

Question 8

Sister chromatids

Answer 8

Two identical strands of DNA joined by a common centromere.

Question 9

Supercoiling

Answer 9

The condensing of chromosomes as they become repeatedly coiled to make them much shorter, wider structures during prophase.

Question 10

Microtubules

Answer 10

Hollow protein tubes seen during the mitosis of animal cells.

Question 11

Spindle fibres

Answer 11

Network of microtubules that collectively form a mitotic spindle in mitosis.

Question 12

Prophase

Answer 12

First stage of mitosis during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears.

Question 13

Metaphase

Answer 13

Stage in mitosis in which chromosomes become arranged at the equatorial plate.

Question 14

Equatorial plate

Answer 14

Also, called the metaphase plate, the figure formed by the chromosomes in the centre of the spindle during mitosis.

Question 15

Anaphase

Answer 15

Stage in mitosis in which sister chromatids are separated, pulled to opposite poles of a cell.

Question 16

Telophase

Answer 16

The final stage of mitosis in which the separated chromosomes reach the op

Question 17

Cytokinesis

Answer 17

The division of the cytoplasm and the plasma membrane, following the division of the nucleus resulting in two cells in mitosis.

Question 18

Cell plate

Answer 18

A membrane that forms midway between dividing plant cells during cytokinesis and later becomes the cell wall.

Question 19

Cyclins

Answer 19

A family of closely related proteins that regulate the cell cycle in eukaryotic cells.

Question 20

Serendipity

Answer 20

Discovery by fortunate accident.

Question 21

Oncogenes

Answer 21

A gene that causes normal cells to change into cancerous tumour cells.

Question 22

Mutagens

Answer 22

Chemical agents that increase the rate of genetic mutation.

Question 23

Tumours

Answer 23

An abnormal growth of tissue that develop at any stage of life in any part of the body.

Question 24

Cancer

Answer 24

A malignant tumour and is named after the part of the body where the primary tumour first develops.

Question 25

Primary tumour

Answer 25

Original histological site of cancerous growth of cells.

Question 26

Secondary tumour

Answer 26

A colony of cancerous cells formed by the spread of cells from a primary tumour [metastasis].

Question 27

Metastasis

Answer 27

The movement of cells from a primary tumour to set up secondary tumours in other parts of the body.

Question 28

Mitotic index

Answer 28

The ratio between the number of cells in mitosis to the total number of cells.