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.

Question 2

Cancer

Answer 2

general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells.

Question 3

Cell plate

Answer 3

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

Question 4

Centrioles

Answer 4

a self-replicating cylindrical organelle that is involved in the process of nuclear division.

Question 5

Centromere

Answer 5

the region joining the two sister chromatids where it becomes attached to the spindle fibres.

Question 6

Chromosomes

Answer 6

linear strand of DNA bonded to proteins in the nucleus of eukaryotic cells that carries the genetic information.

Question 7

Cyclins

Answer 7

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

Question 8

Cytokinesis

Answer 8

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

Question 9

Equatorial plate

Answer 9

the figure formed by the chromosomes in the centre of the spindle during mitosis.

Question 10

Metaphase

Answer 10

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

Question 11

Metastasis

Answer 11

characteristic of malignant tumours of transferring the disease from one organ to another not directly connected with it.

Question 12

Microtubule fibres

Answer 12

hollow protein tubes seen during the mitosis of animal cells.

Question 13

Mitosis

Answer 13

the process where a single cell divides into two identical cells, each containing the same number of chromosomes and genetic content as that of the original cell.

Question 14

Mitotic index

Answer 14

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

Question 15

Mutagens

Answer 15

chemical agents that increase the rate of genetic mutation.

Question 16

Oncogenes

Answer 16

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

Question 17

Prophase

Answer 17

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

Question 18

Sister chromatids

Answer 18

two identical strands of DNA joined by a common centromere.

Question 19

Spindle fibres

Answer 19

network of filaments that collectively form a mitotic spindle in mitosis. They are involved in moving the chromosomes during nuclear division.

Question 20

Supercoiling

Answer 20

twisting in the opposite direction to the turns of the double helix during the first stage of mitosis.

Question 21

Telophase

Answer 21

the final stage of mitosis in which the separated chromosomes reach the opposite poles of the dividing cell and the nuclei of the daughter cells form around them.

Question 22

Tumours

Answer 22

abnormal proliferation of cells, either benign or malignant.