Genetic Information Flashcards
What is Mitosis for?
"Growth" and renewal/replacement of cells Asexual reproduction (cells produced are genetically identical)
What are the stages of Mitosis?
(I)PMAT
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Interphase
Prophase
Metaphase
Anaphase
Telophase
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Mitosis - Interphase
‘Resting phase’
DNA replication, protein synthesis and ATP synthesis take place
Mitosis - Prophase
Chromosomes condense (shorten and thicken)
Any centrioles present move to poles
Spindle begins to form
Mitosis - Metaphase
Spindle fibres extend to cover whole cell
Centromeres line up at equator of cell
Chromosomes arranged singly
Mitosis - Anaphase
Chromosomes pulled apart by spindle fibres attaching onto centromeres
Chromosomes pulled to poles by centromeres contracting
Mitosis - Telophase
Chromatids reach poles (now known as chromosomes)
Cell cytoplasm divides (cleavage furrow = animals, cell plate = plants)
Nuclear membrane reforms
Chromosomes indistinct
What is cytokinesis?
After Telophase, cytoplasm splits
DNA content is halved
What are cancers a result of?
Uncontrolled mitosis
Tumours = irregular mass of cells caused by mutations in genes in cell division
What is Meiosis for?
Sexual reproduction (produces genetically different cells)
What are the stages of Meiosis?
Meiosis 1:
(I)P1M1A1{T1}
Meiosis 2:
{P2}M2A2T2
*{P2} won’t happen unless {T1} occurs
Meiosis - Interphase
DNA replication, protein synthesis and ATP synthesis take place
Meiosis - Prophase 1
Chromosomes condense
Any centrioles present move to poles
Spindle begins to form
Chromosomes arranged in homologous pairs, these pairs overlap at chiasma
Meiosis - Metaphase 1
Chromosomes line up at equator in homologous pairs
Maternal/paternal chromosomes align randomly on each side
Meiosis - Anaphase 1
Chromosomes pair (bivalent) pulled apart by contracting spindle fibres Chromosomes pulled to poles Chiasma break, maternal and paternal chromosome sections pulled to opposite pole of chromosome to which they were joined (random assortment)
