Studied by 6 peopleCell division
the formation of two genetically identical daughter cells
Where are the chromosomes?
in the nucleus
What are chromosomes?
long, thin strings of genes that contain instructions for making new cells
What are genes?
Genes are sections of DNA that control a single genetic trait.
How many chromosomes are in the nucleus of a body cell?
46 chromosomes
How are chromosomes arranged in cells?
23 pairs - one from mother and one from father
How many chromosomes do gametes have?
23 chromosomes
Cell cycle
series of events that cells go through as they grow and divide
Mitosis
asexual reproduction by splitting the nucleus
How long is the cell cycle?
24 hours to several years
When is the cell cycle rapid?
as a baby develops and throughout childhood
When does the cell cycle slow?
after puberty
What areas continue rapid cell division in adults? [4]
the hair follicles, the skin, the blood, the lining of the digestive system
Cell cycle: stage 1 [4]
longest stage
cells grow bigger and increase mass
replicate DNA to form two copies of each chromosome
replicate organelles
Cell cycle: stage 2 [3]
mitosis
one set of chromosomes is pulled to each side
nucleus divides
Cell cycle: stage 3 [1]
cytoplasm and cell membranes divide to form daughter cells
Diploid
46 chromosomes
Interphase [3]
cell grows
cell replicates chromosomes
organelles replicated
Prophase [3]
chromosomes condense
nuclear membrane dissolves
spindle fibres form
Metaphase [2]
nucleus dissolves
chromosomes align in centre
Anaphase [1]
chromosomes moved to opposite poles of cell
Telophase [3]
just before cells split
nuclear membranes reform
spindle fibres dissolve
Cell cycle order
interphase
prophase
metaphase
anaphase
telophase
Note
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