3.2.2 all cells arise from other cells

Question 1

what are the stages of the cell cycle

Answer 1

interphase
mitosis
cytokinesis

Question 2

describe the behaviour of chromosomes and the role of spindle fibres in prophase

Answer 2

chromosomes condense becoming shorter and visible
nuclear envelope breaks down
centrioles move to opposite ends of the cell

Question 3

describe the behaviour of chromosomes and the role of spindle fibres in metaphase

Answer 3

spindle fibres attach at the centromere of the chromosomes
chromosomes move and line up along the equator

Question 4

describe the behaviour of chromosomes and the role of spindle fibres in anaphase

Answer 4

spindle fibres pull the sister chromatids apart to opposite ends of the cell

Question 5

describe the behaviour of chromosomes and the role of spindle fibres in telophase

Answer 5

chromosomes uncoil becoming longer and no longer visible
nuclear envelope reforms around the cytoplasm

Question 6

what is produced at the end of mitosis

Answer 6

4 diploid, genetically identical, daughter cells

Question 7

why is mitosis important

Answer 7

mitosis allows from cell growth
allows for repair of damaged tissue
asexual reproduction

Question 8

how might mitosis lead to cancer

Answer 8

mutations in the genes which control mitosis can lead to uncontrolled cell division
the mass of abnormal cells forms a tumour

Question 9

by which process do prokaryotic cells divide

Answer 9

binary fission

Question 10

describe the process of binary fission

Answer 10

replication of circular DNA
replication of plasmids
division of cytoplasm to produce 2 daughter cells

Question 11

describe how viruses replicate

Answer 11

attachment proteins attach to complementary receptors on the host cell
the capsid, containing nucleic acids, is injected into the host cell
infected host cell aids replication of the virus