Mitosis and meiosis Flashcards
(34 cards)
G1
Cell grows to adult
size may exit to G0
chromosomes are not visible
Interphase
G1 S G2
S
DNA copied
G2
Prepares to divide
checkpoints that make sure the cells ready to divide and that’s what cancels ignore
Mitosis
Nuclear division of chromosomes (sister chromatids)
Prophase metaphase anaphase telophase
Prophase
Nuclear envelope breaks apart
chromosomes begin to form
Centrioles migrate to opposite sides of the cell
Metaphase
Chromosomes line up in the middle of the cell
centrioles go to the ends of the cell
Anaphase
Chromosomes break apart and
the number of chromosomes is doubled
Telophase
Nuclei begin to form occurs with cytokinesis
cleavage furrow
One-gene-one-protein
Theory that a gene is some portion of a chromosome that gives rise to one protein molecule
Meiosis
Cell division that produces reproductive cells in sexually reproducing organisms
Zygote
Diploid cell formed when sperm fertilizes egg
Synapsis
Paring of homologous chromosomes in a diploid cell
Occurs in prophase1 of meiosis
Prophase 1
First phase of meiosis 1 Replicated chromosomes condense Homologous pairs pair up Crossing over occurs Spindle formed Nuclear envelope breaks
Tetrads
During Prophase1 meiosis
Paired set of homologous chromosomes
Metaphase1
Tetrads align at the equatorial plan
Anaphase 2
Breakdown of proteins holding the sister chromatids together at the centromere allowing them to separate
Move towards opposite poles
Telophase 2
Final phase of meiosis 2
same as militia telophase but halved a second time
Meiosis 2
Second division of a two stage process of cell division in sexually reproducing organisms that results in cells with half the chromosome number of the original cell
Gametogenesis
Process
Gametes are produced through combination of meiosis and maturational changes
Spermatogenesis
Effects in seminiferous tubules that produce male gametes
Spermatogonium
Diploid cell that can undergo mitosis to form more spermatogonium, and can also be triggered to undergo meiosis to form sperm
Seminiferous tubules
Narrow coiled tubes that produce sperm in the testes
Oogenesis
Production of female gamete