Chapter 8: Cell Reproduction Flashcards
packing
a series of steps that a cell does to organize its DNA
chromatin
DNA wrapped around proteins (hint: histones)
centromere
the region joining two molecules of DNA
kinetochore
part of the centromere that connects to the spindle fiber (hint: microtubule)
tubulin
a protein that makes up microtubules
microtubules
a hollow cylindrical cytoskeleton element
chromatid
one half-chromosome
motor proteins
proteins within the kinetochore, which depolymerize microtubules and shorten them, causing the chromatids to separate
centrosomes
Structures which are made up of two centrioles, and are the poles from which spindle fibers originate. They help aid chromosomal movement in cell division, and help initiate microtubule formation.
cytokinesis
the division of the cell’s cytoplasm
mitosis
the division of the cell’s nucleus
spindle
the array of microtubules at the metaphase plate
actin
a globular protein that links into chains, forming microfilaments, and is a component of the contractile ring in animal cells
myosin
thicker filaments made of protein
asters
star-like clusters made up of microtubules which originate from the centrosomes
MPF/maturation promoting factor
the activated complex of cyclin and cyclin-dependent protein kinase
proteolysis
the breakdown of proteins into amino acids by enzymes
malignant tumor
a tumor whose cells can spread to other organs and invade surrounding tissues
benign tumor
a tumor that grows to a certain size then stops, and does not spread
Hela cells
the cancer cells of Henrietta Lacks
oncogenes
a cancer causing gene found in viruses and genomes of organisms
proto-oncogenes
a regularly occurring gene that is involved in cell cycle regulation, and has the potential to become an oncogene if altered
metastasis
the migration of cancer cells from their origin
signal transduction pathway
a mechanism linking mechanical or chemical stimulus to a cellular response
transcription factor
a protein that stimulates transcription of genes by binding to DNA
telomerase
an enzyme that catalyzes the lengthening of telomeres
telomeres
repeated DNA sequences at the ends of chromosomes
recombinants
new combinations of genes
gametes/sex cells/germ cells
mature reproductive cell, (hint: a sperm or an egg)
diploid
a cell with two copies of each chromosome
haploid
a cell with one copy of each chromosome
homologous chromosomes
chromosome pairs that have the same genetic composition and are derived from different parents
synapsis
the pairing of homologous chromosomes
chiasma (pl. chiasmata)
the area where crossing over takes place between homologous chromosomes
tetrad
a structure composed of two homologues in synapsis (4 chromatids)
disjunction
the separation of homologous chromosomes
independent assortment
the result of the random orientation of homologous pairs of chromosomes along the metaphase plate
spermatogenesis
formation of sperm
seminiferous tubules
tubes in the testes where spermatogenesis takes place
Sertoli cells
nutrient cells that nourish developing sperm
gonads
gamete producing organs in most animals
oogonium
cells that give rise to the primary oocyte
polar body
a cell that results from an unequal division of cytoplasm during oogenesis, and eventually degrades
zygote
a fertilized egg
