MITOSIS AND CELL CYCLE

study slide set

what is the definition of the life/cycle of an organism?

Period of growth and development from the start of an organism cell to when it produces

what are the 2 main parts of the cell cycle?

interphase and cell division (cytokinesis)

what happens during interphase?

time of growth and duplication of organelles, enzymes, and DNA

what are the 3 stages of interphase?

G1, S, G2

what happens during G1?

interval of cell growth, before DNA replication

What happens during S?

interval of cell growth, when DNA replication is completed

what happens during G2?

interval following DNA replication, cell prepares to divide

what happens during cell division?

separation of duplicated components of a cell into 2 new fully functional cells

what are the 2 phases of cell division?

nuclear division (mitosis) and cytoplasmic division

what are the 4 stages of mitosis?

1. Prophase

2. metaphase

3. anaphase

4. telophase

in which phase of interphase are their molecules;ar brakes to stop cell division?

G1

once a cell cycle has entered________ phase of interphase, the cycle runs to completion

S

what occurs when there is a malfunction of the molecular brakes?

cancer

what types of cells typically stop in interphase?

neurons in human brain (arrested cells do not divide)

what kinds of conditions result in a cell cycle stopping in interphase? what type of organism is an example of this?

adverse, nutrient-deprived amoebas

what is the goal of cell division?

to create new, fully functional cells

what is the goal of nuclear division?

to separate the chromosomes duplicated in S phase of interphase, into 2 new cells

what has to happen prior to cell and nuclear division?

interphase

what are the 2 phases of cell division?

1. mitosis

2. meiosis

3. prokaryotic fission

what types of organisms undergo mitosis/meiosis?

Eukaryotic

what types of organisms undergo prokaryotic fission?

prokaryotic organisms

what types of cells undergo mitosis?

body cells

what types of cells undergo meiosis?

reproductive cells

what is another name for prokaryotic fission?

binary fission

what is the goal of mitosis?

to divide nuclear material in such a way to maintain the original chromosome number and type in each of the resulting 2 cells

how many chromosomes are there in a human cell?

46

what are the 2 roles that mitosis plays in the body cells of multicellular organisms?

growth and cell replacement

what other role does mitosis play in some protistans, fungi, plants, and animals?

asexual reproduction

what is a chromosome?

DNA strand and the protein molecules it is wrapped around

when do chromosomes start to decondense?

telophase

when do the duplicated chromosomes start to condense?

prophase

when do the sister chromatids of the chromosome separate?

anaphase

when are the chromosomes at opposite poles of the cell?

telophase

when do the chromosomes line up in the spindle equator?

Metaphase

when is a chromatid called a chromosome?

once it is separated (anaphase)

when are the chromosomes maximally condensed?

metaphase

in what phase does the microtubules “ratchet” the cell so that it elongates?

anaphase

in what phase does the spindle form?

metaphase

in what phase do centrioles move to opposite poles of the spindle?

prophase

in what phase do microtubules start to assemble?

prophase

In what phase do spindle microtubules become attached to the 2 sister chromatids of each chromosome?

metaphase

in what phase does the cytoplasmic division start to occur?

telophase

in what sates do nuclear membranes form, one around each set of unduplicated chromosomes?

Telophase

in what stage does the nuclear membrane start to break up?

prophase

what is the purpose of mitosis for our bodies?

to end up with 2 daughter cells with the same material as the parent cell

how many daughter cells result?

2

how many chromosomes does a cell about to undergo mitosis start with?

46

how many chromosomes does each cell end up with?

ends with 2 daughter cells each with 46 chromosomes

is the same genetic material sam or different for each daughter cell as the original cell?

it depends on the type of cell division

in which stage is cytoplasmic division completed?

usually occurs between late anaphase and end of telophase

what are the two mechanisms of cytoplasmic division?

cell plate formations and cleavage

which mehcanism of cytoplasmic division do animal cells use?

cleavage

which mechanism of cytoplasmic division do plant cells use?

cell plate formation