chapter 10 test

cell division

how cells reproduce by splitting apart

asexual reproduction

the process of genetically identical offspring from a single parent

sexual reproduction

involves the fusion of two separate parent cells

cell cycle

when the cell grows, prepares for division, and divides to form two daughter cells

interphase

an “in-between” period of growth

mitosis

first stage in cell division; division of the nucleus

cytokinesis

division of the cytoplasm

chromosome

tight packages containing genetic information

chromatin

unwound DNA found in the nucleus

prophase

first phase; chromosomes condense and become visible; nuclear envelope disappears; centrioles move to opposite sides to organize the spindle

sister chromatid

two identical copies of a chromatid

centromere

the thing that hold the two chromatids together

spindle apparatus

controls the movement and separation of chromosomes during division

centriole

helps in the formation of spindle fibers

metaphase

second phase; centromeres line up across the center of the cell; spindle fibers connect the centromere of each chromosome to the two poles of the spindle

anaphase

third phase; centromeres are pulled apart + chromatids become chromosomes; chromosomes separate into two groups near the poles of the spindle

telophase

fourth phase; chromosomes spread out into a tangle of chromatin; nuclear envelope reforms

cyclin

family of proteins that regulate the timing of the cell cycle in eukaryotic cells

growth factor

external regulators that stimulate the growth and division of cells; important during wound healing and embyonic developmentembryonic

cancer

uncontrolled cell growth

tumor

mass created when cancer cells divide uncontrollably

benign tumor

noncancerous

malignant tumor

cancerous

apoptosis

process of programmed cell death

stem cell

unspecialized cells from which differentiated cells develop; doesn’t have particular function

what are some difficulties a cell faces as it increases in size?

demands grow', less efficient in moving nutrients, “information crisis”

how does asexual and sexual reproduction differ?

asexual: genetically identical offspring

sexual: inherit some genetic information from each parent

what are the stages of interphase?

G1, S, G2, M

what happens during the G1 phase?

cell grows and creates new proteins and organelles

what happens during the S phase?

new DNA is created when chromosomes are replicated

what happens during the G2 phase?

preparation for cell division; organelles and molecules required for cell division are produced

what is the role of chromosomes in cell division

allows the DNA to be accurately copied

what are the parts of mitosis

prophase, metaphase, anaphase, telophase (pmat)

what is the difference between cytokinesis in animal and plant cells?

animal cells: cell is pinched by belt of protein threads

plant cells: vesicles holding cell wall line up in the middle to fuse into a cell plate which separates the cell

what are two functions of mitosis

growth and reproduction

how is the cell cycle regulated?

controlled by regulatory proteins both inside and outside the cell

what are the checkpoints in the cell cycle?

G1, G2, M

what does the G1 checkpoint check?

cell size, nutrient amount, DNA damage and growth factors; happens after G1

what does the G2 checkpoint check?

DNA damage and DNA replication completeness; right before prophase, after G2

what does the M checkpoint check for?

“spindle checkpoint”; chromosomes attached to the spindle properly, make sure there are an equal amount of sister chromatids; between prophase and metaphase

how do cancer cells differ from other cells?

cancer cells do not respond to the signals that regulate the growth of most cells

what are some causes of cancer?

defects in genes that regulate cell growth and division; defects could come from smoking, radiation exposure, defective genes and viral infection