Cell Division

Question 1

What is cell continuity?

Answer 1

All cells develop from pre-existing cells.

Question 2

What are chromomsomes?

Answer 2

Coiled threads of DNA (which form genes) and proteins that become visible in the nucleus at cell division.

Question 3

What is a diploid cell?

Answer 3

Cell that has 2 sets of chromosomes i.e has 2 of each type of chromosome in the nucleus.

Question 4

What is a haploid cell?

Answer 4

Cell that has one set of chromosomes i.e only has 1 of each type of chromosome in nucleus.

Question 5

What is a homologous pair?

Answer 5

Consists of 2 chromosomes that each have genes for the same features at the same positions.

Question 6

What is interphase?

Answer 6

Phases in the cell cycle when the cell isn’t dividing.

Question 7

What is mitosis?

Answer 7

Form of nuclear division in which 1 nucleus divides to form 2 nuclei, each containing the same number of chromosomes with identical genes.

Question 8

What is cancer?

Answer 8

A group of disorders in which certain cells lose their ability to control both the rate of mitosis and the number of times mitosis takes place.

Question 9

What is meiosis?

Answer 9

Form of nuclear division in which the 4 daughter nuclei contain half the chromosome number of parent nucleus.

Question 10

What are the 4 stages of mitosis?

Answer 10

Prophase, metaphase, anaphase and telophase.

Question 11

What phases does a new cell have to go through before it can divide again?

Answer 11

1) . Produces material it will need
2) . Grows larger
3) . Reproduces to form new cell.

Question 12

What symbolises haploid?

Answer 12

n

Question 13

What symbolises diploid?

Answer 13

2n

Question 14

What cells are haploid?

Answer 14

Sperm and egg

Question 15

What does the cell do in interphase?

Answer 15

Produces mitochondria, chloroplasts, etc and chemicals for growth.

Question 16

What happens in prophase?

Answer 16

1) . End of interphase, chromosomes contract and become visible.
2) . Each chromosome appears as a duplicated strand.
3) . Fibres appear in cytoplasm of cell.
4) . Nuclear membrane starts to break down.

Question 17

What happens in metaphase?

Answer 17

1) . Nuclear membrane completely broken down.
2) . Chromosomes thicken more.
3) . Chromosomes line up across the centre of cell
4) . Spindle fibres attach to centromeres
5) . Each chromosome has 2 fibres attached, 1 each side.

Question 18

What happens in anaphase?

Answer 18

1) . Spindle fibres contract and pulls chromosomes apart.
2) . Each strand pulled to opposite ends of cell.
3) . Identical set of genes on each side.
4) . Shortest stage.

Question 19

What happens in telophase?

Answer 19

1) . Chromosomes at each end turn to chromatin.
2) . Spindle fibres break down.
3) . Nucleolus reforms
4) . Nuclear membrane starts to form around chromatin.

Question 20

How do animal cells divide?

Answer 20

Cleavage furrow.

Question 21

How do plant cells divide?

Answer 21

1) . Vesicles containing cellulose gather between 2 nuclei and join to form cell plate.
2) . 2 cell walls will form in cell plate and eventually split.

Question 22

What is the function of mitosis in unicellular organisms?

Answer 22

1). Reproduction

Question 23

What is the function of mitosis in multicellular organisms?

Answer 23

1) . Produce new cells

2) . Responsible for growth, renewal and repair of cells.

Question 24

What are malignant tumours?

Answer 24

1) . Uncontrolled multiplication of abnormal cells
2) . Malignant tumours invade other cells and move around body.
3) . Cancer cells can divide indefinitely.

Question 25

What is the movement of cancer cells called?

Answer 25

Metastasis.

Question 26

Name for altered genes that form cancers?

Answer 26

Oncogens.

Question 27

What are cancer causing agents called?

Answer 27

Carcinogens.

Question 28

Where does meiosis occur in the body?

Answer 28

Testes and ovaries to produce gametes.

Question 29

What are the functions of meiosis?

Answer 29

1) . Asexual Reproduction without increasing number of chromosomes in offspring.
2) . Allows new combinations of genes i.e variation within species.

Question 30

How many cells are produced by meiosis?

Answer 30

4

Question 31

How many cells are produced by mitosis?

Answer 31

2