3.4 Cell Division Part 4 Flashcards
What are cdc mutations?
cell division cycle mutations
Which genes are commonly mutated?
kinases
What are kinases needed for?
phosphorylation of proteins involved in cell signaling and metabolic pathways
How are most kinases found in a cell?
down regulated state
What activates kinases?
cyclins
What are the main functions of cell cycle checkpoints
monitor the mitotic process to ensure things are going smoothly before proceeding to the next stage
What is the main difference between mitosis and meiosis?
mitosis has a lack of genetic variation while meiosis has a lot of genetic diversity
What is crossing over?
exchange of genetic information between homologous chromosomes
What is the first stage of meiosis?
prophase I
What occurs during prophase I?
homologous chromosomes undergo synapsis
What is synapsis?
homologous chromosomes pairing up
What occurs during synapsis?
chromosomes are so close together they undergo crossover events
What is a bivalent?
synapsed pair of chromosomes
What is the bivalent number equal to?
the haploid number
What is a tetrad?
bivalents that have condensed; two pairs of sister chromatids
What is the chiasma?
point on sister chromatids where they remain intertwined during metaphase I
What is the glue that holds non-sister chromatids together during meiosis I?
chiasmata
What is a dyad?
half of a tetrad
At the end of anaphase I, what has occurred?
there are a haploid number of dyads at each end pole
What occurs during telophase I?
cytokinesis divides everything in two and the nuclear membrane reforms around the dyads
