Week 2 Flashcards
By which day does blastocyst implant into wall of uterus?
6
Describe Cullen’s sign
Bruising in subcutaneous fat tissue around umbilicus - sign of ruptured extrauterine pregnancy
Where is the pregnancy located at
a - 12 weeks
b- 16 weeks
c- 20 weeks
up to pubic bone
halfway btwn pubic bone and belly button
belly button
Gestational sac should be seen at 4-5 weeks or if bHCG is over _____
2500
What is the cut off for perinatal loss?
28 d after birth
What is the cut off that differentiates between spontaneous ab and stillbirth?
loss over 20 weeks
Describe Chadwick’s sign
bluish/purplish exam in normal pregnancy cervix
What is friable cervix?
Bleeding with sexual intercourse
Name 5 important tests for pregnant women
1) hCG
2) progesterone
3) blood type and Rh
4) CBC (white count, h&h)
5) prenatal panel
Where are primordial germ cells located at
a) week 2
b) week 3
c) week 4
d) week 5
a) epiblast
b) wall of yolk sac
c) migrate to developing gonads
d) arrive in gonads
________, bizarre growths that contain different tissues, form when misdirected PGC’s do not die
Teratomas
True or false - Oogonia never undergo mitosis
false, only undergo mitosis during embryonic development
What makes chromosomes homologous?
Have individual alleles of SAME genes located at SAME locus
True or false - bio selection of an allele for one trait has NOTHING to do with selection of an allele for another trait
TRUE DAT
Independent assortment :)
Primary oocytes remain in _________ and do not finish meiotic division before puberty
Prophase I
Secondary oocytes are arrested in _________ until sperm penetrates
Metaphase II
Define spermiogenesis
Spermiogenesis - the generation of sperm ( haploid cells differentiate towards mature sperm, acquire tail and an acrosome). Spermatids –> Spermatozoa
_________, the last phase of spermiogenesis, is created after spermatid disengages excess cytoplasm and is released into the semniferous tubule
Spermatozoa
______________ stimulates oocyte meiosis, follicle ovulation, and progresterone secretion.
Luteinizing hormone
_________ stimulates uterine proliferative phase, thins cervical mucus, stimulates pituitary to secrete LH
Estrogen
_________ secreted by luteal cells stimulates uterine secretory phase
Progesterone
Describe the difference between positive predictive value and sensitivity
sensitivity = true positive / total # of pts with condition
PPV = true positive / # of pts who test positive
Describe a Robertsonian Translocation
Short arm of one acrocentric chormosome is exchanged with long arm of another creating a large chromosome (two long arms) and a fragment that is often lost - 5% of DS
The larger the nuchal translucency, the more likely the baby will have _____ or ______ syndrome
cardiac or chromsomal
What are characteristics of trisomy 18?
clenched fist, overriding index finger, VSD, rock bottom feet, choroid plexus cyst. 90% die within first 6 months.
In second trimester screen analytes (hCG, inhibin, estriol, AFP)
1) DS
2) trisomy 18
1) high HCG and high inhibin
2) all low
What are characteristics of trisomy 13?
polydactyly, cleft lip, cleft palate, midline defects (heart, brain, abd), most die within 4 years, 60% are miscarried
Describe the characteristics of Turner Syndrome
XO; short stature; short neck;infertility; cardiac, endocrine and kidney abnormalities
During the ______________ phase of the ovarian cycle, granulosa cells proliferate and theca cells develop with LH receptors
pre-antral follicular
Pre-antral and antral follicular phases- major difference
pre-antral is hormonal independent, and antral is hormonal dependent
The LH surge towards end of first half of ovarian cycle, induces expression of _____________ which activates the primary oocyte.
maturation promoting factor
Differentiate between primary, second, and tertiary follicles
1) metaphase I
2) granulosa proliferate, thecal cells become visible
3) antrum forms
Class 5 antral follicles that do not become dominant undergo ________
artesia
Once the secondary oocyte is penetrated by sperm, it completes meiosis II and produces _________ and __________
one large ovum, 2nd polar body
The LH surge also stimulates two other things, what are they?
Causes follicular rupture and oocyte extrusion; causes corpus luteum to make progresterone
LH and FSH both stimulate estrogen production from follicle. How?
LH stimulates thecal cells to make androgen from cholesterol
FSH stimulates granulosa cells to make aromatase –> converts androgen to estrogen
After oocyte is captured by sweeping movement of ______________ of oviduct, fertilization occurs at _______
fimbrae of oviduct, ampula
Differentiate between the corpus luteums fate when it is fertilized vs not fertilized
fertilized - hCG from ST allows CL to grow –> make progesterone x4 months
not fertilized - cells apoptose –> corpus albicans –> progesterone secretion is lost –> triggers menstrual bleeding
Describe the three phases of fertilization. Where are the acrosomal enzymes released? ( acrosin and hyalurandiase)
1) penetration of the corona radiata
2) penetratation of the zona pellucida
3) oocyte and sperm fuse
Acrosomal enzymes released to penetrate of zona pellucida and to promote lyosomal enzyme release by oocytes (slow block of polyspermy)
Differentiate between slow block and fast block of polyspermy
fast block - depolarization of ZP (no more sperm can attach)
slow block - ZP permeability changes (no more sperm can pass)
During embryo transport, there is a delay at the _____________
utero tubal junction
Egg enter uterine cavity as _________ before it is implanted as a blastocyst
morula - day 3 - 16 cell inner cell mass
Describe the steps in blastocyst formation
Zona pellucida degenerates
Inner cell mass forms (embryoblast)
Outer cell mass forms (trophoblast)
Implantation (normally in the posterior superior uterine wall) occurs when the trophoplast cells invade the ________ on day 6
uterine epithelium
After menstrual phase, the ___________ phase begins, which is induced by estrogen. An LH surge at day 14 causes ovulation.
proliferative (follicular) phase
After ovulation, the ________ phase begins, which is induced by progesterone.
progestational (secretory) phase
What remains after the menstrual phase?
bottom layer of the endometrium
What are the layers of the endometrium? (3)
compact, spongy, basal (bottom)
There is a delay at the ___________ junction where fertilization occurs
ampullary isthmic junction
Where does implantation normally occur? (part of uterine wall)
posterior superior
(week 2) What are the two functions of the synctiotrophoblast as part of outer cell mass?
1) secretes hCG (initiates decidual rxn to take in glycogen and nutrients)
2) helps implant embryo
(week 2) By which day is there complete implantation of the embryo into the endometrium and covering of implantation location by a fibrin plug?
day 10
(week 2) Which cells surround the amniotic cavity? Which surround the blastocystic cavity (which becomes the primary yolk sac?
epiblasts, hypoblasts
(week 2) The synchtiotrophoblast layer secretes hCG to send signal to ovary to keep making _____________, which maintains the secretory portion of the uterine cycle
progesterone
(week 2) What occurs to hCG levels in ectopic pregnancy and why?
Start out high but uterine tube cannot support placenta so will taper off
hCG peaks at _____ weeks and then drops off until ___ weeks
10, 24
(week 2) Describe the differences between the two layers of the extraembryonic mesoderm
Sphlancnic mesoderm surrounds yolk sac
Somatic mesoderm lines cytotrophoblast and becomes connecting stalk
(week 2) The _____________ forms between the 2nd yolk sac and cytotrophoblast
chorionic cavity
(week 2) What are the two functions of the secondary yolk sac?
hematopoiesis
primordial germ cells
(week 2) Hypoblasts, as part of the primary yolk sac, are referred to as
Heuser’s membrane
(week 2) What three types of cells make up the chorion
1) synctiotrophoblast
2) cytotrophoblast
3) extraembryonic somatic mesoderm
(week 2) Maternal blood lacunae form in the endometrium by invasion of the synctiotrophoblast and chorionic villi establishing the _________________
early placenta
(week 2) What are the two components of placenta generated in the second week of pregnancy?
1) endometrium
2) chorion
The appearance of the __________ marks the beginning of the third week and of gastrulation
primitive streak
The primitive streak establishes the position polarity of the embryo. (3)
dorsal ventral
right left
cranial caudal
The ______ and ______ membranes on the primitive streak represent two areas where epiblasts and hypoblasts are fused.
buccopharyngeal
cloacal
What are the three layers (all derived from epiblast) are formed during gastrulation
ectoderm, mesoderm, and endoderm
At the end of the fourth week, the primitive streak disappears. If it does not, what does it form?
Sacrococcygeal teratoma - most common tumor in new born
At 15 days, invagination of epiblast cells occurs, which displaces the ________ to create the definitive _______ which once established allows inwardly moving epiblast cells to create _____________
hypoblast cells, endoderm, mesoderm
The _________ layer is responsible for collagen, cartilage, muscle, bone, kidney, blood and spleen
mesoderm
The __________ layer is responsible for the neural crest cells (involved in cranial bone, nerve, and adrenal medulla etc) the pituitary, the brain, and more superficial organs
ectoderm
The _______ layer is responsible for sex cells, lung, thymus, liver,, the thyroid and the gut
Endoderm
In 3rd week, ______ development from paraxial mesoderm begins (cells migrate to 2nd most cranial part of primitive node)
somite development
By the third week, the formation of the _____ which stimulates neurulation is complete
notochord
Cells that migrate to the most cranial part of the primitive node form the
notochord
Cells that igrate to the most caudal part of the primitive node form the ___ which is responsible for formation of the ______
extraembryonic mesoderm, chorion
Cells that migrate to mid point of primitive node (between cranial and caudal) form the ____ which is responsible for the _____
intermediate mesoderm, urogenital system
Cells that migrate to second most caudal part of the primitive node form the _____ which is responsible for the _____
lateral plate, body wall
The _________ formed by endoderm sets the limit for cranial migration of notochordal cells and induces formation of the forebrain
prechordal plate
The hollow _____________ grows granially from walls of primitive pit
notochord process
The ventral wall of notochordal process fuses with the endoderm to form the _____________
notochordal plate
What are the three parts of the primitive streak?
groove, pit, node
Which of these would be indicated by low AFP levels
a) fetal demise
b) normal pregnancy
c) molar pregnancy
d) trisomy
e) all of the above
e
Which of these would be indicated by high AFP levels
a) neural tube defects
b) twins
c) abd wall defect
d) low birth weight
e) all of the above
e
Low/high AFP levels may indicate an error in ______ or fetal demise
dating
Karyotyping, during which cells are arrested in metaphase and stained with Geimsa stain, gives ___________ information about chromosomes
structural - detects large deletions, inversions, duplications and translocations
Locus specific, aiphoid/centromeric repeat, and chromosome specific are the three types of probes used in _________
FISH!
In FISH analysis, nuclei are labeled to visualize ________ and interphase nuclear are labeled to determine ____ which can be used to determine degree of mosaicism
chromosome structure, number
What is a con of microarray analysis and cell free DNA?
will detect only gain or loss, not balanced rearrangement
Which of the following is NOT an example of a balanced chromosomal abnormality?
a) inversions
b) insertions
c) duplications
d) isochromosomes
c- types are direct tandem and inverted
TRUE OR FALSE: Unbalanced and balanced abnormalities in chromosomes are reproductively lethal
FALSE, unbalanced only, however balanced mutations can lead to unbalanced inheritance
_________ is the primary hematopoietic tissue of the myeloid tissues whereas __________ is the primary hematopoietic tissue of the lymphoid tissues
bone marrow, thymus
Name the four most immature types of cells that are going to be committed
myeloblasts, monoblasts, pronormoblasts, megakaryoblasts
Hemapoietic stem cells arise ____________ (time frame) after embryological development in yolk sac
3-6 weeks
After 6 to 12 weeks, HSC’s migrate to the ________ which is the chief site of fetal blood cell formation
liver
After fourth months, HSC’s migrate to the bone marrow where they stay until puberty after which hematopoiesis is restricted to the _______________
axial skeleton
How does hemolytic disease of the newborn cause massive edema?
When baby’s blood cells are destroyed by mother, liver is overwhelmed by demand for hematopoiesis –> does not make albumin
In ________, the nucleus cannot synthesize DNA for daughter cells, therefore the cytoplasm in cells is still blue due to RNAs and the cells contain hgb
folate deficiency
In _____________, too many lobes are seen in the cells
B12 deficiency
Which of Freud’s aspects of personality are the original reserve of all psychic energy (drives and impulses based on most primitive needs)?
a) id
b) ego
c) superego
d) Freud did not believe in such things
a)
In the latency period of sexual development, sexual strivings are suppressed vby the:
a) id
b) ego
c) superego
d) Freud did not believe in such things
c)
According to Erikson, basic trust vs mistrust is established within ____ to ____ years of age and failure can lead to seeing relationships as disappointing or too dangerous to rely on
0 to 1
According to Erikson, autonomy vs self doubt is established within ____ to ____ years of age
1 to 3
According to Erikson, initiative vs guilt is established within ____ to ____ years of age
3 to 6
Why does erythropoietin level rise with 2ndary polycythemia but not primary?
in 2ndary polycythemia, the tumor secretes EPO
Reticuloycte maturation is inversely related to _____________ due to accelerated release from the marrow
hct%
Megakaryocytes produce what types of cells?
platelets
________ occurs in response to an infection when immature neutrophils are dumped into the blood
left shift / bandemia
Which of the following myeloid trophic factors triggers IL-1 production
a) granulocyte/macrophage CSF
b) granulocyte CSF
c) neupogen
d) monocyte/macrophage CSF
d
In neutrophil development, a ________ is indicated by primary granules whereas a _________ is indicated by secondary granules. Myeloblasts never contain granules.
promyelocyte, myelocyte
Describe the outcomes of the following lymphoid trophic factors: IL-1 IL-2 IL-3 IL-4 IL-5
fever T-cell development bone marrow IgE, b-cells IgA, eosinophils
Which of the following is charged, polar, and contains an OH group?
a) glucose
b) glycerol
c) glycine
d) lactate
e) aspartate
D
glucose and glycerol are contain OH group
glycine and aspartate are charged
Why do lipids associate in H2O?
The amount of water order decreases when lipids come together, increasing entropy, decreasing G
_________ acts as the buffer of blood. it is a weak acid that loses protons to become ________
carbonic acid, bicarbonate
When are respiratory compensatory mechanisms used versus metabolic compensatory?
respiratory - when caused by changes in PcO2
metabolic - when caused by changes in bicarbonate
Define type of R group and pKA for the following
a) Aspartate and Glutamate
b) Lysine and Arginine
a) 4.5, positively charged
b) 10.5, negatively charged
What is the difference between a nucleotide and a nucleoside?
Nucleoside has no phosphate group, nucleotides have 1-3
TRUE OR FALSE: Recessive loss of function mutations result in loss of activity of half of proteins
true
For dominant disorders, disease frequency is equal to
heterozygous frequence
For X-linked dominant disorders, the frequency of affected females is ____ the frequency of affected males
2X
What is similar about both viral and bacteria genomes?
No introns
The human genome is 30% genes (28.5% are introns or noncoding) and 45% _________
transposons - small piece of DNA that inserts itself into another place in the genome
Mutations in LINE and SINE (transposons) have been linked to several disorders including hemophilia, muscular dystrophy and breast cancer. In SINES, ____ repeats are the most common types of mutations.
ALU
_____ describes stretches of conserved gene order on chromosomes
synteny
What are the four mechanisms that create new genes?
intragenic mutations, gene duplication (globin, IgG chains), DNA segment & shuffling, horizontal transfer
________ are tandem repeat sequences that display length variations
simple sequence length polymorphisms (SSLPs)
microsatelites and minisatellites also tandem repeats
What are absolutely required for DNA replication (4)
a) primer
b) free 3’ OH
c) DNA polymerase
d) source of nucleotides
____________ creates double strand breaks to relieve supercoiling induced by ATP-driven DNA helicase and prevent DNA tangling during replication
DNA topoisomerase
Acyclovir is a _____________ inhibitor used in treatment of oral herpes. It gets converted to acyclo-GTP which gets incorporated in DNA and induces
DNA polymerase, chain termination
Human ____________ is required for gene expression and DNA replication and is a target of inhibitory drugs
human type II topoisomerase
X-rays and O radicals cause single strand breaks and uracil formation and can be corrected by
a) base excision repair
b) nucleotide excision repair
c) recombination repair
d) mismatch repair
a
IR, UV light and X-rays cause double strand breaks that can be corrected by
a) base excision repair
b) nucleotide excision repair
c) recombination repair
d) mismatch repair
c
________ of cytosine produces uracil
Deamination
Which of the following repairs DNA injuries caused by UV radiation or carcinogenic substances? (ex thymine-thymine binding)
a) base excision repair
b) nucleotide excision repair
c) recombination repair
d) mismatch repair
b
In ___________, MutL and MutS detect issue and MutH recognizes methyl groups on template DNA strand in order to decide which copy to cut
mismatch repair
Xeroderma pigmentosum is caused by inherited defects in which DNA repair mechanism?
nucleotide excision repair
In homologous recombination, a ds break can be fixed after strand invasion occurs and produces a ________________ which depending on the direction can induce cross over
double holliday junction
In site specific recombination, movement of __________ occurs between non-homologous sites
transposons
Which of the following is not a primary structure peptide?
a) vasopression
b) glucagon
c) angiotensin
d) all of the above are
d
What are the two classes of molecular chaperones?
heat shock proteins and chaperonins
What occurs to entropy and free energy of the protein in the free energy funnel model of protein folding
both decrease
Which of the following diseases is not an amyloidosis?
a) cystic fibrosis
b) parkinson’s
c) type II DM
d) beta thalessemia
e) cruetzfeldt-jacob
d
What change in single AA residue causes sickle cell anemia?
glutamine –> valine
If the pH is less than the pKa of the molecule, then the _________ form will be present, and if the pH is higher than the pKa, the ________ form will be present
protonated, deprotonated
Gel exclusion chromatography separates molecules by
a) charge
b) size
c) affinity to ligand
d) charge and size
b - SDS page also separates by size charge is ion exchange affinity to ligand is affinity charge and size is native 1D page 2 dimensional SDS page separates by PI and size
What is the difference between cosubstrate and prosthetic group
Prosthetic groups associate permanently with active site of NZ, cosubstrates are temporary
Adenylate kinase is involved in converting AMP and ATP to
two ADPs
Which coenzymes is NOT a carrier of functional groups?
a) Coenzyme A
b) NAD
c) NADP
d) FAD
e) FMN
a) carries acyl groups, SH groups form thioester bonds with organic acids
S-adenosyl methionine is a ________ donor for most bio ______
methyl group, methylations
_________ is the structural unit of a chromosome, consisting of a length of DNA coiled around a core of histones (which require 8 proteins)
nucleosome
Chromatin’s dynamic structure allows swapping of _______ which is carried out by ATP-dependent chromatin remodeling complex
histone proteins and nucleosomes
______ proteins relax chromosomes and activate transcription while ______ removes acetyl groups and causes chromatin to repack. Which is a target for anticancer treatment?
HAT, HDAC
HDAC!
Which small RNA subtype is involved in post transcriptional gene silencing?
a) snRNA
b) snoRNA
c) miRNA
d) scRNA
c
Which RNA polymerase transcribes
a) protein coding (mRNA ) and snRNA genes
b) rRNA genes
c) tRNA genes
a) II
b) I
c) III
_______ is a cyclic peptide toxin derived form mushrooms that strongly inhibits RNA polymerase II and weakly inhibits RNA polymerase III
alpha-amanitin
_______ inhibits mtRNA polymerase, but does not affect other eukayrote RNA polymerases
Rifampin
Which of the following is not involved in opening and unwinding DNA helix?
a) helicase
b) endonuclease
c) gyrase
d) topoisomerase
b
What is the order for transcription factors of RNA polymerase II?
D - recognizes Tata box
B - recgonizes BRE, positions RNA polymerase at start of transcription
F - stabilizes RNA polymerase interaction
E - attracts and regulates H
H - unwinds DNA at transcription start, releases RNA polymerase from promoter
_______ proteins, when bound to corresponding region, can cause DNA strand to loop back onto where polymerase is and turn expression on
Enhancer
While RNA is being made, 5’ cap, 3’ tail and intron splicing occur. 5’ cap involves the addition of a 5’ to 5’ ______________ that includes 7-methylguanosin
triphosphate bridge
___ is present at 5’ donor splice site in intron while ___ is present at 3’ acceptor splice site in intron
GU, AG
The premRNA splicing pathway involves the cut 5’ end of the intron being covalently linked to a the adenine on the 3’ end, resulting a loop structure called a ____ that is later released
lariat
Exon skipping, mutually excluse exons, alternative 5’ donor site, alternative acceptor site, and intron retention are all examples of alternative splicing that lead to __________
exon shuffling
A ____________ is a site where a sequence rsembles an authentic splice site and may be selected during aberrant splicing
cryptic splice site
_____ proteins are involved in selecting splice sites
SR, serine/arginine
Abnormal processing of B-globin can lead to Beta-thalessemia in all but which of the following?
a) formation of three exons
b) activation of cryptic splice sites
c) exon skipping
d) new exons incorporated
a) that’s normal
____________ binds to poly a tail and interact with 5’ by making a circular mRNA
poly a binding protein
Which of the following is NOT a functional domain of transcription factors?
a) dimerization domain
b) activation domain
c) repression domain
d) DNA binding domain
c
Glucocorticoid receptor is an example of a DNA binding domain class called?
Zinc Fingers, other one is basic domain (+) charge
True or false: The two types of dimerization domains are leucine zipper and helix-loop-helix domains, although the latter can also bind DNA
true
_____ is an essential transcription factor for muscle development and is this type of dimerization domain
basic helix loop helix
______ genes code for helix turn helix class transcription factors that control anterior posterior patterning
Homeobox - control fundamental architectural plan of developing embryo
What are the 4 factors in P4 medicine?
personalized, predictive, preventative, and participatory
Define spermatogonia
Stem cell (diploid) that is renewed –> meiosis I –> primary spermatocyte –> meiosis II –> spermatid –> spermiogenesis
