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47 Cards in this Set
- Front
- Back
what 3 functions does cellular division serve?
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1. growth
2. repair 3. reproduction |
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what are the two types of cell division?
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1. meiosis
2. mitosis |
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what does mitosis produce?
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2 genetically identical daughter cells, conserving the chromosome number (2n)
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what does meiosis produce?
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cells with half the chromosome number of the parent cell (n)
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when does meiosis occur?
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in sexually reproducing organisms
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what does a replicated chromosome consist of?
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two sister chromatids, where one is an identical copy of the other
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what does a chromosome consist of?
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a highly coiled an condensed strand of DNA
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what is the centromere?
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region that holds two chromatids together
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what is the kinetochore?
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a protein on the centromere that attatches the chromatid to the mitotic spindle during cell division.
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regarding mitosis, what is karyokinesis?
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nuclear division
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regarding mitosis, what is cytokinesis?
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cell division.
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prior to mitosis, what happens to the cell?
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it undergoes a period of growth and replication of genetic material called interphase
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a cell spends about 90% of its life in what phase of the cell cycle?
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interphase
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during interphase are individual chromosomes visible?
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no, the DNA is uncoiled and known as chromatin
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what are the 5 major phases of the cell cylce?
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G1, S, G2, (interphase) mitosis, & cytokinesis
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what are the 4 stages of mitosis?
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PMAT
Prophase Metaphase Anaphase Telophase |
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what is prophase?
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first step in mitosis. chromosomes condense; spindles form
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what is metaphase?
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chromosomes align
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what is anaphase?
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sister chromatids separate
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what is telophase?
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new nuclear membranes form
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when a cell is in interphase, what is the chromatin like?
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threadlike, loose, NOT condensed
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do plant cells have centrosomes?
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no, but they do have microtubule organizing centers.
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what is cytokenesis and when does it occur?
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it is the division of the cytoplasm and it occurs following telophase.
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in what type of cells does a cleavage furrow form during cytokenesis?
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animal cells
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in what type of cells does a cell plate form during cytokenesis?
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plant cells
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do plant cells have centrioles?
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NO
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do plant cells have centrosomes?
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NO
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what is meiosis?
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the form of cell division that produces gametes with the haploid chromosome number (n)
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what are gametes?
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sex cells : sperm and ova
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what does meiosis involve?
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two divisions of primary sex cells, resulting in 4 haploid cells called gametes
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what are the two stages of meiosis?
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meiosis I & meiosis II
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what is meiosis I?
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homologous chromosomes separate
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what is meiosis I AKA?
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reduction division
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what is meiosis II?
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similar to mitosis; sister chromatids separate
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is meiosis when does crossing over occur?
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prophase I
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in prophase I of meiosis what is synapsis?
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homologous chromosomes intertwine (forming a tetrad=2 sets of sister chromatids)
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between which chromosomes does crossing over occur?
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only between homologous chromosomes, NOT sister chromatids of the same chromosome (they are identical)d
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after recombination are sister chromatids still identical?
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noo
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in meiosis what occurs in metaphase I?
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tetrads line up at the equatorial plane, and spindle fibers attatch
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in meiosis, what occurs in anaphase I?
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the homologous pairs separate and are pulled to opposite poles of the cell. AKA disjunction.
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in meiosis what occurs during telophase I?
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a nuclear membrane forms around each new nucleus. sister chromatids still constitute each chromosome, so meiosis II occurs next
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what is meiosis II AKA?
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the second meiotic division
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do hydra and yeast undergo budding or binary fission?
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budding
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do amoebae, paramecium, algae and bacteria undergo budding or binary fission?
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binary fission
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at what stage does the synaptonemal complex form?
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prophase of meiosis
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what is synapsis?
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in meiosis 1; each chromosome pairs up precisely with its homologue forming a synaptonemal complex.
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homologous chromosomes separate when? sister chromosomes?
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homologous = meiosis I
sister = meiosis II (similar to mitosis!) |