Final Lab Flashcards
Mitosis and cytokinesis are often referred to collectively as “cellular division” why are they more accurately called cellular division?
Because the DNA in the chromosomes are duplicated
Does the cell cycle have a beginning and an end?
No because they repeat
Mitosis interphase
Chromosomes replicated
Mitosis prophase
Sister chromatids condense and spindle starts to form nuclear membrane begins to dissociate into vesicles
Mitosis prometaphase
Nuclear membrane has completely dissociated into vesicles and the spindle is fully formed. Sister chromatids attach to spindle via kinetochore microtubules
Mitosis metaphase
Sister chromatids align along the metaphase plate
Mitosis anaphase
Sister chromatids separate and individual chromosomes move toward poles as kinetochore microtubules shorten. Polar microtubules lengthen and push poles apart
Mitosis telophase and cytokinesis
Chromosomes decondense and nuclear membranes re-form. Clevage furrow separates the 2 cells
If a nucleus has eight chromosomes during interphase, how many chromosomes does it have during metaphase?
Eight
If a nucleus has eight chromosomes during interphase how many does it have after mitosis is complete
Eight in each cell
Why would we choose embryonic mass of cells to study stages of mitosis
Because embryonic cells undergo rapid cell divisions
Which stage of mitosis most often associated with the beginning of cytokinesis
Late anaphase
What region of a riot has the most mitotic activity
The tips because of rapid cell division
How does cytokinesis differ in plants versus animal cells
Plant cell- cell plate is perpendicular to the axis of the spindle apparatus
Animal cell-begins on the periphery of the cell and pinches inward
Why is pinching of the cytoplasm inadequate for cytokinesis in plant cells
Plant cells need cell walls so if the cell pinches off there would be 2 cells in one cell wall
What is a cell plate and in what stage of mitosis does it form
Cell divider that is the beginning stage of a new cell wall forms in telophase
Why would shuffling genetic material to produce new combinations of characteristics be advantageous to a species
The offspring in this species will be more genetically diverse and may be more able to adopt changing environments
Synopsis occurs after chromosomal DNA has replicated how many chromatids are involved in crossing over of a homologous pair of chromosomes
4
Major differences between meiosis and mitosis
Meiosis has 2 cell divisions and is vital for sexual reproduction
If a nucleus eight chromosomes when it begins meiosis how many does it have after telophase 1 and 2
4 and 4
Prophase one
Homo Logus chromosomes synapse to form bivalents and crossing over occurs chromosomes condense and the nuclear membrane begins to fragment
Prometaphase one
Nuclear membrane completely fragments and bivalents become attached to Kinetochore microtubules
Metaphase one
Bivalents A line along the metaphase plate
Anaphase one
Homologous chromosomes separate and move toward opposite poles
Tele phase 1 and cytokinesis
Nuclear membranes reform and the chromosomes decondense the two cells are separated by a cleavage furrow
Prophase two
Sister chromatids condense and the spindle starts to form nuclear membrane begins to fragment
Prometaphase two
Nuclear membrane completely fragments sister chromatids attached to spindle via Kinetochore microtubules
Metaphase two
Sister chromatids align along the metaphase plate
Anaphase two
Sister chromatids separate and individual chromosomes move toward poles as kinetochore microtubules shorten polar microtubules lengthen and push poles apart
Telophase two and cytokinesis
Chromosomes decondense and nuclear membranes re-form clevage furrow separates the 2 cells into 4 cells
Purpose of mitosis
Increase number of cells manage cells growth and asexual reproduction
Purpose of meiosis
Reduce diploid cells produce egg and sperm cells
Number of cells produced in mitosis
Two haploid
Number of cells produced in meiosis
Four haploid
Number of nuclear divisions in mitosis
One
Number of nuclear divisions in meiosis
Two
Haploid or diploid of resulting cells mitosis
Dihaploid
Haploid or diploid of resulting cells in meiosis
Haploid
Mitosis genetically identical cells
Yes
Genetically identical cells meiosis
No
Pairing of homologous mitosis
No
Pairing of homologous meiosis
Yes
Occurrence of crossing over mitosis
No
Occurrence of crossing over meiosis
Yes
