chromosomes snd mitosis

Question 1

what is a chromosome

Answer 1

the genetic material in a nucleus
(coiled up length of DNA molecules)

Question 2

each chromosome carries a large number of genes. what is a gene

Answer 2

something that controls the development of different characteristics

Question 3

how many PAIRS of chromosomes do human cells have

Answer 3

23

Question 4

what is mitosis

Answer 4

the stage of the cell cycle when the cell divides

Question 5

what is mitosis used for (in multicellular organisms)

Answer 5

growth or replacing cells that have been damaged

Question 6

what are the two main stages of the cell cycle

Answer 6

•growth and DNA replication
• mitosis

Question 7

what is the cell cycle

Answer 7

1) in a cell that is not dividing, the DNA is spread out in long strings
2) before it divides, the cell has to grow and increase the amount of subcellular structures (mitochondria + ribosomes)
3) it then duplicates its DNA - so there’s one copy for each new cell. the DNA is copied and forms X-shaped chromosomes
4) the chromosomes line up at the centre of the cell and cell fibres pull them apart.
5) membranes form around each of the sets of chromosomes. these become the nuclei of the two cells.
6) the cytoplasm and cel membrane divide