Mitosis Flashcards
What is the purpose of mitosis?
mitosis is the portions of cell division in eukaryotes which attempts to produce daughter cells that are identical genetic copies of the parent cell (barring any mutations) and are used in asexual reproduction, growth and repair
How many times does a cell divide during mitosis?
once
What kinds cells are produced at the end of mitosis and how many?
two identical diploid somatic (non-reproductive) cells
What are sister chromatids?
duplicated chromosomes which are joined together at the centromere and therefore still considered a single chromosome
Briefly describe what happens during prophase.
DNA is beginning to condense
The nuclear membrane is beginning to break down
Spindles begin to form
Briefly describe what happens during pro metaphase.
The chromosomes are connected to the the spindle microtubules at the centromere and the M checkpoint insures proper attachment of the microtubules to the centromere.
Nuclear membrane, ER, and golgi finish breaking down
Briefly describe what happens during metaphase.
chromosomes line up on the equatorial plate due to a “tug of war” by the microtubules
Briefly describe what happens during anaphase.
the centromeres separate and the sister chromatids, now considered separate chromosomes, are pulled towards opposite poles of the cell
Briefly describe what happens during telophase.
chromosomes begin to decondense and nuclear envelopes begin to reform
Is cytokinesis part of mitosis?
NO! cytokinesis is the portion of cell division in which the cytoplasm is separated and the cell splits into two daughter cells, whereas mitosis is the division of the genetic material housed in the nucleus
What processes in meiosis lead to the formation of genetically different gametes?
- ) Independent assortment which mixes non-homologous chromosomes
- ) Crossing over which mixes genetic material between homologous chromosomes
How many times does the cell divide during meiosis?
twice
What kind of cells are produced at the end of meiosis and how many?
Haploid gametes
Four
Briefly describe the difference between prophase 1 and 2.
In prophase 1: homologous chromosomes pair up and crossing over occurs between non sister chromatids of a homologous pair
In prophase 2: chromosomes made up of sister chromatids so not form homologous pairs
Briefly describe the difference between metaphase 1 and 2.
In metaphase 1: homologous chromosomes (homologues) align together on the equatorial/metaphase plate
In metaphase 2: each chromosome aligns independently on the metaphase plate.
Briefly describe the difference between anaphase 1 and 2.
In anaphase 1: homologues are separated and pulled towards opposite poles of the cell
In anaphase 2: the centromeres separate and the sister chromatids, now considered different chromosomes, are pulled towards opposite pole of the cell
Is interphase part of mitosis or meiosis?
NO!
What important event(s) occur in interphase that are required for cell division?
Nuclear DNA must be copied during S phase to create sister chromatids
Briefly describe what happens during cytokinesis
The cytoplasm separates and the cell splits into two
How is cytokinesis different in plant and animal cells?
In animal cells a ring of microfilaments contract forming a cleavage furrow until the cell is pinched in two.
In plant cells a cell plate forms between the two cells where vesicles full of cell wall material build a new cell wall between the daughter cells.
What is the purpose of meiosis?
meiosis is the portions of cell division in eukaryotes which attempts to produce haploid gametes that are genetically different for the purposes of sexual reproduction.
