Cell Cycle Flashcards
list the three phases of interphase
G1 S G2
what makes spindle fibers
centrioles
what do spindle fibers do
pull the chromosomes apart
list the four phases of mitosis
prophase, metaphase, anaphase, telophase
list the three phases of the cell cycle
interphase, mitosis, cytokineis
metastasize
the movement of cancer cells from one body tissue to anouther
two types of cells that never undergo mitosis
skin and nerve cells
what are the two types of tumors, which one is cancerous, and why
benign and malignant; malignant is cancerous because it can metastasize
three reasons cells divide
- grow/ develop
- replace old/ dead/ damaged cells
- make gametes
why does MITOSIS occur in our cells
to replace cells and grow and develop
why does MEIOSIS occur in our cells
to make sex cells
where does meiosis occur in males and females
testes and ovaries
when does meiosis occur in males/females
puberty/ before birth
what separates during anaphase II
sister chromatids
how many chromosomes are in human somatic cells
46
how many chromosomes are in human gametes
23
diferenciation
when a cell changes to become the type of cell it is going to be
cyclins
chemicals that stimulate the division and differentiation of new cells during growth
regeneration
the process of growing back lost body parts
vegetative reproduction
when new plants grow from the stems, leaves, or roots of an existing plant
prokaryotes divide by the process of what
binary fission
when does DNA replication occur
s phase of mitosis
in the first phase of binary fission the DNA is …
replicated
after two nuclear divisions in meiosis, how many cells result
4
two types of gametes
sperm and egg
sexual reproduction
when separated pieces of parent organisms develop into new individuals
budding
when a parent organism produces offspring by growing a tiny replica of itself
crossing over
the exchange of genes between pairs of homologous chromosomes
genes
regions that code for specific traits or characteristics of organisms
what checkpoint occurs in the G2 phase of interphase
mitotic spindle check point
adapation
the process of change in living populations over time
genetic variation
differences among members of a population
cleavage furrow
a groove that forms through the middle of the parent cell that divides the cytoplasm
sister chromatids
identical strands of DNA that result from replication
asexual reproduction
a type of reproduction when one parent produces identical offspring by cell division
a prokaryote’s DNA is ___ and ____
circular and single
when in meiosis do HOMOLOGOUS chromosomes line up in the middle of the cell
metaphase I
in metaphase 1 __ occurs allowing the resulting sex chromosomes to be different
crossing over
chromosomes become distinctly visible in what phase of mitosis
phrophase
what separates in anaphase of mitosis
chromosomes
how many daughter cells are made from mitosis occuring in one parent cell
2
what is the cell formed when an egg and a sperm fuse
zygote
what is the process of the fusion of an egg and sperm
fertilization
what cell has two complete sets of chromosomes
diploid
what cell has one complete set of chromosomes
haploid
mitosis
the division of the nucleus of a cell
cytokinesis
the division of the cytoplasm of the cell
if the somatic cells = 14 chromosomes, then the haploid # is
7
is gametes = 16 chromosomes, then # are in the somatic cells
32
if somatic cells = 28, the diploid # is
28
what are the two processes that occur during meiosis that allow for genetic variation
independent assortment and crossing over
in what phase does crossing over occur
phrophase I
tetrad
a pair of homologous chromosomes
synapisis
the process of two homologous chromosomes coming together
genes are mutated by what
mutagens
what are the two genes that work to control the cell cycle
protooncogenes and tumor suppressor genes
protooncogenes act as a what
gas pedal/speed up division
tumor suppressor genes act as a what
brakes/ slow down division
is a zygote diploid or haploid
dipoid
telomeres
the ends of chromosomes that are lost every time cell division occurs
three causes of aging
telomeres, cancer, and apoptosis
what is necrosis
an unplanned/damaged death
trisomy
an extra copy of a chromosome
monosony
a missing copy of a chromosome
what causes trisomy and monosomy
nondisjunction
what happens if apoptosis occurs too often
you get degenerate diseases
what occurs if mitosis is unchecked
tumors or cancer
what occurs when a gene that makes an enzyme for repairing DNA doesn’t work properly
werners syndrom
why do people shrink when they get older
apoptosis of bone cells
apoptosis
a planned, programmed death
what is made during spermogenesis and how many
4 sperms
what is made during oogenesis and how many
1 ova and 3 polar bodies
how is oogenesis different than spermogenesis
unequal cytokinesis
what are polar bodies and what happens to them
small cells made from unequal cytokinesis that disolve
which is larger the egg cell or the sperm cell and why
egg because it has more cytoplasm
name two ways chromosomes can be changed
substitution or deletion
what three things can be determined by looking at a karyotype
gender, change in number of chromosomes, change in structure
do all cells have the same life cycle
no
advantages of sexual and asexual reproduction
sexual=diversity
asexual=easy to regrow
disadv. of sexual and asexual reproduction
mutations
why is genetic variation so important
so we can adapt
name the 4 chromosomal mutations
deletion, duplication, inversion, translocation
deletion
a piece of a chromosome falls off/ is lost
duplication
a piece is copied
inversion
a piece falls off, flips around, and reinserts itself
translocation
a piece of a non homologous chromosome breaks off and attaches to another chromosome
name the three checkpoints
g1,g2, mitotic spindle
g1 checkpoint
is the cell big enough
g2 checkpoint
is the cell big enough to divide and has DNA completely replicated
mitotic spindle checkpoint
are the chromsomes aligned on the spindle
what is trisomy 18
Edward’s syndrome; fatal, mental retardation, small brain, cleft lip, flat face, deaftness
trisomy 21
down’s syndrome; small turned up eyes, small mouth and ears, small flat nose, heart defects, mental cognitive delays
trisomy 13
pataus syndrome; impacts nervous system, head and face size, heart bone growth
monosomy x
turner’s syndrome; underdeveloped sexually, sterile, short stature, webbed neck
trisomy xyy
Jacob’s syndrome; excess acne, very tall, aggressive, delayed emotional maturity
trisomy xxy
Klinefelter’s syndrome; underdeveloped testes, sterile, feminine characteristics
trisomy xxx
metafemale; taller, small head, learning disabilities, normal sexual development, fertile, delayed motor skills
