mitosis

Question 1

what are the main stages of the cell cycle

Answer 1

interphase
prophase
metaphase
anaphase
telophase
cytokinesis

Question 2

define mitosis

Answer 2

cell division that produces 2 genetically identical daughter cells from a parent cell

Question 3

why do cells need to carry out mitosis

Answer 3

growth and repair tissues
replace cells

Question 4

what happens during interphase

Answer 4

• G1: cell organelles replicate
• S: DNA replication
  -G2: increase in proteinsynthesis and ATP synthesis

Question 5

what happens during prophase

Answer 5

• chromosomes condense and become visible
• nuclear membrane breaks down centrioles move to opposite poles of the cell
• spindle fibres form

Question 6

what happens during metaphase

Answer 6

• spindle fibres attach to centromere
• chromosomes are lined up at the equator of the cell

Question 7

what happens during anaphase

Answer 7

• spindle fibres contract splitting the centromere
• v-shaped sister chromatids are separated and pulled apart to opposite poles of the cell

Question 8

what happens during telophase

Answer 8

• identical chromosomes have reached the poles
• spindle fibres break down
• a new nuclear membrane forms around each group of chromosomes
• chromosomes uncondense

Question 9

what happens during cytokinesis

Answer 9

the cytoplasm divides into 2 to create 2 separate daughter cells

Question 10

how do prokaryotic cells replicate

Answer 10

a process called binary fission
- the circular DNA and the plasmids replicate
- the copies of circular DNA move to separate poles of the cell
- the cytoplasm divides to produce 2 daughter cells
- each cell contains a single copy of the circular DNA but a variable number of plasmids

Question 11

how do viruses replicate

Answer 11

• they use a specific host cell to replicate
• the virus attachment protein binds to a specific complimentary receptor protein on a specific host cell
• the viral DNA/RNA is injected into the host cell
• the host cell uses the viral genetic material and its own ribosomes and enzymes to synthesise viral proteins
• the viral particles are formed and release from the host cell