cell cycle

Question 1

what are the 3 steps of the cell cycle?

Answer 1

1. prophase
2. mitosis
3. cytokinesis

Question 2

what is a chromosome?

Answer 2

a long strand of DNA called chromatin

Question 3

what the structure of a chromosome?

Answer 3

chromatin stands and a centromere

Question 4

what cells have 46 chromosomes

Answer 4

diploid cells have homologous pairs of chromosomes (23 pairs)

Question 5

describe the 3 stages of the interphase:

Answer 5

1. Gi: cell growth, all organelle are replicated
2. S: DNA synthesis (change the form of chromosomes not the number)
3. G2: another growth phase and where DNA is checked

Question 6

describe the 4 stages of mitosis:

Answer 6

1. prophase: all DNA is unravelled as chromatin, the nuclear envelope breaks down and DNA condenses into x-shape chromosomes
2. metaphase: chromosomes move into the equator of the cell by spindle fibers
3. anaphase: spinal fibres contract pulling the chromosomes to opposite sides lf the cell so they form chromatids
4. two nee nuclear envelopes for and chromatids become chromosomes

Question 7

describe cytokinesis:

Answer 7

1. the cytoplasm divides and pulls the cell into 2 forming 2 identical daughters cells