Lecture 1 Flashcards
Chromosome
DNA coiled around histones, not visible unless compacted during replication
centromere
divides the chromosome into arms, depending where it is gives the shape of the chromosome. p= short arm q=long arm
diploid
2n (little n). one set form dad one set from mom
chromatin
dense chromosomes around hsitones
euchromatin
first level of dna packing. beads on a string
heterochromatin
second level of dna packing, coiled telephone cord
centrosome
organelle located near the nucleus in the cytoplasm that divides and migrates to opposite sides of the cell during mitosis. microtubules grow out called the mitotic spindle fibers
kinetochore microtubules
attach to the kinetochore of each chromosome (2 kinetochores per replicated chromosome) 1 on each side. many arms for each chromsome
polar microtubules
go to the center and overlap
aster microtubules
come of centrosome and branch away from midline. provide an anchor for the pulling motion
microtubules
alpha and beta tubulin subunits. plus end is away from centrosome. neg end is at centrosome. polymerization grows and depolymerization shrinks.
motor proteins
walk down the tubulin microtubules. energy dependant (atp). required for spindle formation (make it stable)
aneuploidy
abnormal chromosomes. hallmark of cancer. motor proteins help prevent this
cell cycle
S phase is dna synthesis 12 hours. M phase is mitosis and is 1 hour of the 24. g1, s, g2, m
interphase
g1, s, g2. gaps is for the cell to grow and get big enough to divide.
Mitosis
PMAT
prophase
start with thickening and coiling of chromosomes. mitotic spindle forms as centromeres migrate, nuclear envelope disappears.
metaphase
centrosomes are on opposite sides, chromosomes line up in middle, attach to a kinetochore microtubule
anaphase
sister chromatids separate. can from J or V depending on where centromere is. align at each pole.
telophase
chromosomes start to uncoil. nuclear envelope reforms around each set. cytokinesis splits the cell.
silent mutatons
no change in dna sequencing
missence mutation
changes the dna sequence. can multiply over time causing a issue
uncontrolled cell division
cancer. happens when mitotic checkpoints arent followed
benign tumor
not cancerous, often can be removed and dont comeback
malignant tumor
invade nearby tissues, and can metastisize
metastasis
blood or lymph. regional (near original tumor) distant (far from original tumor). liver, lungs, bones, lymph nodes. need systemic therapy
gene mutations
born with. increases chance of cancer
acquired. lifestyle habits. old, smoking, virus, radiation, ecct. inflammation, lack of excercise. obesity
cancer test
oral surgeon, or ear/nose/throat surgeon. MRI, CT, PET
TNM-T
t0/in situ
t1=1-2 cm
t2=2-4
t3=4+
t4a=moderate advanced local disease. not spread into nearby tissue. resectable
t4b= advanced local disease. spread into nearby tissue. non resectable
TNM-N
n1= ipsilateral lymph node less than 3 cm n2a=ipsilateral node 3-6 cm n2b=2 ipsilateral nodes less than 6 cm n2c= contralateral node n3= greater than 6 cm
TNM-M
m0=no metastisis
m1=metastasis
meiosis
take a 2n cell and get 4 1n haploids
meoisis 1
Prophase= produces genetic diversity through random arrangement and crossing over (chiasma). Metaphase= line up in pairs anaphase= homolog pairs seperate telophase= seperates to haploid 2N
homolog pairs
lined up in meiosis one. called bivalent chromosomes and are said to be in synapsis
meiosis 2
basically mitosis with no DNA replication
ploidy
number of full single sets, not including duplicated. This is little n
N (big N)
number of full single sets including replications
primordial germ cells
cells that give rise to gametes in both males and females, in the yolk sac. 4-6 weeks they migrate from yolk sac, wall of gut tube, mesentery of gut, dorsal body wall. reside in loose mesenchymal pouches on . pGCs that get stranded on migration is teratoma.
gametogenesis
producce gametes
spermatogenesis
testes have spermatogonia. consatantly go through mitosis. support by sertoli cells. spermatogonia (diploid 2N) to primary spermatocytes (diploid 4N), secondary spermatocytes Haploid 2N), spermatids (haploid 1N)
oogenesis
primary oocyte frozen in prophase 1. when signalled by hormone continues into 1 egg and 3 polar bodies. asymmetrical oogensis. secondary oocyte is large and gets the nutrients.
fertilization
secondary oocyte (egg) is in metaphase 2 and only continues with a sperm.
zona pellucida
glycoprotein layer prevents polyspermy
cleavage
fertilized egg starts to divide. blastomere. 32 is morula.
chromosomal abnormalities
50% of all conceptions aborted.
Downs
trisomy 21. 95% from error in gametogenesis.
nondisjunction
error in separating. correlated to age
translocation
21 gets attached to a other chromosome (usually 14) 3-4% of downs
robertsonian translocation
rearrabgement between 14 and 21
mosiacism
extra 21 lost in cleavage. half cells have a different make up
penetrance
degree to which syndrome effects patient. complete if you have the gene its full blown
incomplete degrees of severity
