Bio week 9+10 - Sheet1 Flashcards
cell division
the process by which a single cell generates new daughter cells
mitosis
a method of eukaryotic cell division that results in daughter cells that are genetically identical to the parent cell
meiosis
method of eukaryotic cell division that results in daughter cells that have half the genetic information of the parent cells
interphase
a stage of the cell cycle in which normal metabolic function occurs, and cell prepares for cell division
G1 stage of interphase
cell gathers nutrients and other resources from its environment and performs normal metabolic functions
S stage of interphase
stage in which DNA synthesis (replication) occurs
G2 stage of interphase
final preparations for mitosis
prophase
1st stage of mitosis. Chromosomes condense. Spindle fibers form. Nuclear membrane disassembles. Nucleolus disappears.
centrioles
cellular organelles comprised of microtubules. assist in cell division
metaphase
3rd stage of mitosis. chromosomes align at the equatorial plane of the cell
anaphase
4th stage of mitosis. sister chromatids move toward opposite ends of the cell
kinetochore
a multi protein complex attached to each chromatid at the centromere. causes shortening of the spindle fibers to pull the chromatid toward the pole.
centromere
the site where the chromatids are attached, formed of nitrogenous bases
telophase
spindle fibers disassemble. nuclear membrane re-forms. chromosomes uncoil. nucleolus re-forms.
cytokinesis
process during which the cell contents are split between the two new daughter cells
cleavage furrow
an indentation of the plasma membrane that pinches in toward the center during cytokinesis
proto-oncogens
code for proteins that encourage cell division
tumor-suppressor genes
code for proteins that discourage cell division
p53
gene that identifies if the cell’s DNA is damaged before DNA synthesis. If damaged, p53 causes the cell to self-destruct
apoptosis
process whereby a cell digests itself from the inside out.
mutagens
agents that mutate or chemically damage DNA
carcinogens
mutagens that cause cancer
tumor
mass of cells not normally found in a certain portion of the body
benign tumor
cell mass that does not fragment and spread beyond its original area of growth
malignant tumors
tumors that may spread of invade other parts of the body
metastasize
tumor cells that move from the original site and grow new tumors in other regions
zygote
original single cell that results from the union of an egg and sperm
determination
cellular process of deciding which genes a cell will express when mature
differentiated
a cell that has become a particular cell type
haploid
cells that have a single set of chromosomes. = one complete set of genetic information
diploid
cells that carry two coplete sets of their genetic information
gamete
eggs and sperm
fertilization
joining of the genetic material from two haploid cells
homologous chromosomes
have the same order of genes along their DNA
non-homologous chromosomes
have different genes on their DNA
meiosis I
reduction division in which the chromosome number in the two cells produced is reduced from diploid to haploid. includes prophase I, metaphase I, anaphase I and telophase I
prophase I
chromosomes condense. spindle fibers form. nuclear membrane disassembles. synapsis and crossing-over occur.
metaphase I
chromosomes align on equatorial plane as synapsed pairs.
anaphase I
homologous chromosomes separate from each other. chromosomes move toward cell’s poles. reduction occurs (diploid to haploid)
segregation
the separation and movement of homologous chromosomes to the opposite poles of the cell
independent assortment
during segregation, homologous pairs segregate independently of each other
telophase I
spindle fibers disassemble.chromosomes uncoil. nuclear membrane re-forms. nucleoli reappear.
meiosis II
includes prophase II, metaphase II, anaphase II and telophase II. The two daughter phase from meiosis I divide resulting in 4 cells. the events in the division sequence of meiosis II are the same as those that occur in mitosis.
prophase II
chromosomes condense. spindle fibers form. nuclear membrane disassembles. nucleoli disassemble.
metaphase II
chromosomes alighn at the equator in unpaired manner
anaphase II
chromatids separate and begin to move to cell’s poles
telophase II
nuclear membrane re-forms. chromosomes uncoil. nucleoli reappear. spindle fibers disassemble.
nondisjunction
occurs when homologous chromosomes do not separate during meiosis. usually reults in cell death, if not, the resulting gamete will have an extra chromosome
monosomy
having one chromosome when there is normally a pair of homologous chromosomes
trisomy
having three chromosomes when there is normally a pair of homologous chromosomes
karyotype
picture of an individual’s chromosomal makeup
down syndrome
chromosome number 21 trisomy
cardiovascular system
the organ system that pumps blood around the body. contains blood, heart and blood vessels. heart –>arteries–>arterioles–>capillaries–>venules–>veins–>heart
arteries
the vessels that carry blood away from the heart and distribute it to the organs
capillaries
the thinnest blood vessels wheere exchange of materials between the blood and tissues that surround the vessels take place.
formed elements
cells and platelets that are suspended in a watery solution called plasma that make up blood
plasma
the watery matrix that contains the molecules and cells of the blood
red blood cells
small disk shaped cells that lack a nucleus. distribute repirtory gasses
anemia
a condition in which a person has a reduced oxygen carrying capacity due to little iron causing not enough hemoglobin to be able to transport oxygen.
platelets
thrombocytes. formed element in the blood. fragments of white blood cells that are essential for clotting
heart
responsible for providing the energy to pump the blood throughout the body
atria
thin walled sacs of the heart that reveive blood from the veins of the body and empty into the ventricles
ventricles
the powerful muscular chambers of the heart whose contractions force blood to flow through the arteries to all parts of the body
semilunar valves
valves in the aorta and pulmonary arteries that prevent the flow of blood backwards into the ventricles
Mitral valve
the left atrioventricular valve
tricuspid valve
the right atrioventricular valve
