Mitosis

Created by bigdaddymac 

Upgrade to
remove ads

cell division

cellular reproduction.
-unicellular organisms: one cell divides, reproduce entire organism.
multicellular organisms: development from a fertilized cell, growth, repair.

cell cycle

the life of a cell from formation to its own division.

most cell division results in...

daughter cells with identical genetic information, DNA.

meiosis

produces nonidentical daughter cells.

genome

all the DNA in a cell: can consist of single or many DNA molecules.

chromosomes

Packaged DNA molecules in a cell.
-each species has a set number of chromosomes (humans 46, hedgehogs 90).

somatic cells

(nonreproductive cells) have two sets of chromosomes.

gametes

have half of chromosomes (humans 23)

before cell division:

DNA replicated, chromosomes condense.

sister chromatids

duplicated chromosomes

centromere

site where chromatids most closely attached.

what is chromatin made up of?

DNA and proteins

mitosis

division of genetic material in nucleus.

cytokinesis

division of cytoplasm.

mitotic (M) phase

mitosis and cytokinesis.

interphase

90% of the cycle; cell growth and copying of chromosomes in preparation for cell division.

eukaryotic cell division

-mitosis
-cytokinesis

overall cell cycle

-mitotic phase
-interphase

interphase

-g1 phase (first gap; cell growth)
-s phase (synthesis; cell growth and chromosome duplication)
-g2 phase (second gap; cell growth)

what is being synthesized in the S phase of interphase?

DNA

mitosis

prophase
prometaphase
metaphase
anaphase
telophase

at what stage is the cell just prior to mitosis?

G2

G2 of interphase

-nuclear envelope surrounds nucleus.
-centrosome has duplicated.
-chromatin has duplicated (but not yet condensed).

centrosome

microtubule organizing center. has two centrioles. part of the mitotic spindle.

mitotic spindle

apparatus of microtubules that controls chromosome movement during mitosis.
-includes centrosomes, spindle microtubules, and asters.

aster

radial array of short microtubules extending from each centrosome.

prophase

chromatin condenses into sister chromatids; assembly of spindle microtubules begins, centrosomes migrate to opposite poles as spindle microtubules grow out from them.

kinetochores

a structure of proteins associated with specific sections of DNA at each centrosome.
-a chromosome has 2 kinetochores facing in opposite directions.

prometaphase

nuclear envelope fragments; chromatids get kinetochores; some spindle microtubules attach to kinetochores and jerk back and forth; nonkinetochore microtubule attachments also form.

metaphase

-centrosomes at opposite poles.
-chromosomes line up at the metaphase plate, the midway point between the spindle's two poles.
-kinetochores arranged so for each chromosome, one kinetochore attached towards each pole.

anaphase

sister chromatids separate (cohesion proteins cleaved); each chromosome moves along kinetochore microtubules toward opposite poles.
-microtubules shorten by depolymerizing at kinetochore ends.
-nonkinetochore microtubules from opposite poles overlap and push against each other, elongating cell.

telophase

genetically identical daughter nuclei form at opposite ends of the cell; nuclear envelopes form; chromosomes become less dense; spindle dissolves.

what material is the metaphase plate made of?

nothing it is imaginary.

cytokinesis

separation of cytoplasm occurs differently in animal and plant cells.
-each new cell gets its share of cytosol, organelles, etc.

cytokinesis (animal cell)

cytokinesis occurs by cleavage; a process of forming a cleavage furrow, or contractile ring of actin microfilaments associated with myosin, that pinches the parent cell in two.

cytokinesis (plant cell)

cytokinesis occurs by forming a cell plate; coalesced vesicles containing cell wall materials, that eventually grows to fuse with membrane around cell, dividing cell into two.

centrosome, centriole, centromere

centrosome: microtubule organizing center that is part of the mitotic spindle.
-centriole: this is one of the two bodies marking the location of the centrosome.
-centromere: this is the tight point of connection between two sister chromatids (region of specific DNA sequences where chromatids attach most closely).

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set