28 terms

Chp. 8 Cellular Basis of Reproductoin and Inheritance

BIO 101
cell division
when a cell undergoes reproduction
structures that contain most of the cell's DNA
binary fission
"dividing in half." Prokaryotes use this.
DNA in a loose state
sister chromatids
two copies of identical DNA molecule. They are joined together tightly at the "waist", or centromere.
where sister chromatids are joined.
cell cycle
ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division into two cells.
where most of cycle occurs. Cell's metabolic activity is very high. Has three phases (G1, S, G2)
mitotic phase (M phase)
when cell actually divides. Two stages, mitosis and cytokinesis.
nucleus and its contents divided and are evenly distributed, forming two daughter nuclei. Has five stages.
usually begins before mitosis ends, cytoplasm is divided in two.
Mitosis has five stages
Prophase, prometaphase, metaphase, anaphase, telophase.
mitotic spindle
chromosomes depend on this for movement. Football-shaped structure of microtubules that guides the separation of the two sets of daughter chromosomes.
clouds of cytoplasmic material that in animal cells contain pairs of centrioles.
cleavage furrow
in animal cells cytokenisis occurs by cleavage. Cleavage furrow is a shallow indentation in the cell surface.
cell plate
membranous disk of vesicles containing cell wall material that has collected at the middle of the parent cell.
growth factor
protein secreted by certain body cells that stimulates other cells to divide.
density-dependent inhibition
a phenomenon in which crowded cells stop dividing.
anchorage dependence
most animal cells exhibit this: they must be in contact with a solid surface to divide.
cell cycle control system
a cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle.
abnormally growing mass of body cells.
spread of cancer cells beyond original site.
somatic cell
typical human body cell that has 46 chromosomes
homologous chromosome
two chromosomes of matching pair of sister chromatids.
contain pair of homologous chromosomes. diploid number is 46
egg and sperms cells collectively. Each gamete has a single set of chromosomes: 22 autosomes plus a sex chromosome, either X or Y.
haploid cell
only one memeber of each homologous pair: human number is 23.
type of cell division that produces haploid gametes in diploid organisms.