AP Bio - Cell Division

mitosis

process by which a cell divides to create 2 identical daughter cells, includes the phases prophase, metaphase, anaphase, and telophase

interphase

cell grows and develops, replicates DNA, contains phases G1, S, G2, and M

prophase (including prophase 2)

first and longest phase of mitosis in which chromosomes condense and the nuclear membrane disappears, spindle fibers begin to form

metaphase (including metaphase 2)

chromosomes line up on the middle of the cell, single file

anaphase (including anaphase 2)

spindle fibers pull sister chromatids to opposite poles of the cell

telophase (including telophase 2)

final stage of mitosis, nuclear membrane begins to form, cells begin to separate, DNA uncoils

meiosis 1

separates homologous chromosomes, forms 2 cells

meiosis 2

separates sister chromatids, forms 4 cells

daughter cells

cells produced by cell division

what produces four different daughter cells?

meiosis

what produces two identical daughter cells?

mitosis

somatic cells

body cells, diploid

diploid cells

cells that contain two sets of chromosomes (2n)

haploid cells

cells that contain only one set of chromosomes (n)

cell cycle

process in which cells reproduce

cdk

cyclin dependent kinase, what is activated by cyclin

cyclin

broken down by cdk, found in the reproductive process of eukaryotic cells

MPF

maturation promoting factor, promotes the m stage in the cell cycle

when are levels of cyclin the highest?

increases the most in the G2 phase, breaks down in the m phase

when are levels of cdk the highest?

they remain the same throughout the cellular process

when are levels of MPF the highest?

when the cell is approaching the m phase

cancer

disorder in which some of the body's cells lose the ability to control growth

how does cancer occur?

a mutation causes the cell to bypass regular checkpoints decreasing the span of the cell cycle, the cells reproduce more quickly, lack density and anchorage dependence

density dependence

cells will stop dividing when they run out of room to reproduce

anchorage dependence

cells can reproduce when they are attached to other cells or some sort of tissue

prophase 1

chromosomes become visible, nuclear envelope breaks down, tetrads form, crossing over occurs

metaphase 1

homologous chromosomes line up side by side in the middle of the cell

anaphase 1

homologous chromosomes are seperated by spindle fibers, pulled to opposite poles of the cell

telophase 1

2 daughter cells are formed, each daughter cell contains only one chromosome of the homologous pair, is haploid

spindle fibers

made of microtubules, assist in cell division by pulling chromosomes to opposite sides of cells

centrosomes

organelles that produce microtubules (spindle fibers), where they root from

centromeres

areas where the chromatids of chromosomes attach

chromatids

"sister" parts of a chromosome

homologous chromosomes

chromosomes that are relatively the same size and share the same spot for the same gene

G1 phase

phase when the cell grows and organelles are copied

G0 phase

cell is not dividing and is not preparing to divide

G2 phase

phase of the cell cycle in which the cell grows again

S phase

DNA is replicated

genetic variation

differences between genes in an individual in comparison to the population

mutation

random change in genes

crossing over

homologous chromosomes in tetrads exchange portions of chromatids

independent assortment

random distribution of pairs of genes to different chromosomes to gamete cells

random fertilization

genetic variation caused by the fact that any sperm can fertilize any egg

histones

protein molecules around which DNA is tightly coiled in chromatin

synapsis

pairing of homologous chromosomes (tetrads), allows possible crossing over

tetrads

paired set of homologous chromosomes

chromatin

unwound DNA

G1 checkpoint

checks for cell size and proper replication of organelles

S checkpoint

checks for DNA damage, can potentially repair damaged DNA

M checkpoint

checks that chromosomes are correctly attached to spindle fibers

apoptosis

programmed cell death

amplification cascade

Advantage of second messenger signal transduction pathways is the possibility of amplified response

phosphorylation cascade

A series of enzyme-catalyzed phosphorylation reactions commonly used in signal transduction pathways to amplify and convey a signal inward from the plasma membrane.