General Principles Week 8 Exam Flashcards
Triple test performed on a pregnant woman at 18 weeks of gestation reveals low levels of alphafetoprotein
(AFP). Amniocentesis confirms these findings. The mother is a known alcoholic and smoker.
Low AFP levels are associated with which of the following conditions?
a. Omphalocele
b. Fetal alcohol syndrome
c. Turner syndrome
d. Trisomy 21
e. Neural tube defects
d. Trisomy 21
A 71-year-old male noticed a painless lump on his forearm, which grew steadily over the next 8 months.After MRI and biopsy a diagnosis of soft tissue sarcoma was made. No metastases were detected. Thepatient was offered chemotherapy in combination with immunotherapy with LAK-cells.
LAK cells are:
a.
T cells and NK cells activated by IL-2
b.
B cells activated by IL-4
c.
Macrophages activated by IFN-gamma
d.
Treg cells activated by IL-6
Which cell in fibrous connective tissue is primarily responsible for making extracellular matrix?
a.
Fibroblasts
b.
Osteoblast
c.
Chondroblasts
d.
Osteoclasts
a.
Fibroblasts
Opsonization is the process by which:
a.
Bacteria are made more easily phagocytized
b.
The alternate pathway of complement is activated
c.
Chemokines attract neutrophils to the site of infection
d.
Neutrophils migrate from the blood through the endothelium to reach the site of infection
a.
Bacteria are made more easily phagocytized
The enzyme responsible for the synthesis of mRNA during transcription is:
a.
RNA primase
b.
RNA gyrase
c.
RNA polymerase
d.
RNA topoisomerase
c.
RNA polymerase
A 22-year-old female has a history of recurrent herpes simplex rash on her lips over the last three years.She had treatment with antiviral medicines with minimal success. The doctor decided to addimmunostimulatory medicine to increase internal antiviral immune factors.
Which cytokines play the main role in antiviral immunity?
a.
G-CSF
b.
TNF
c.
Type I IFNs
d.
Type II IFNs
c.
Type I IFNs
A 48-year-old female complains of difficulty swallowing, loss of appetite, weight loss (12 kg over the lastthree months), irritability and progressive fatigue. On examination: exophthalmia (see the picture)though the thyroid gland is not enlarged. The Doctor suspects Graves’ disease.
What antibodies can be tested to confirm the diagnosis?
a.
Ab thyroid-stimulation hormone receptor
b.
Ab to ds-DNA
c.
Ab to acetylcholine receptors
d.
Ab to gluten and gliadin
a.
Ab thyroid-stimulation hormone receptor
When it comes to fungi, what kind of spores looks like asexual spores formed by a (joint)?
a.
Conidia
b.
Arthroconidia
c.
Spherules
d.
Blastoconidia
b.
Arthroconidia
In a healthy patient, the most populous leukocytes are
a.
Eosinophils
b.
Monocytes
c.
Basophils
d.
Lymphocytes
e.
Neutrophils
e.
Neutrophils
Steady state plasma concentration is typically achieved following:
a.
1-2 half lives
b.
Not dependent on the half-life of the drug
c.
3-4 half lives
d.
4-5 half lives
d.
4-5 half lives
The interaction between RANK and RANKL activates the differentiation of which cell and promotes whatoutcome?
a.
Osteoclasts; bone resorption
b.
Osteoprogenitor cells; bone resorption
c.
Chondroblasts; bone formation
d.
Osteoblasts; bone resorption
a.
Osteoclasts; bone resorption
Autopsy is conducted for an 82-year-old male who died due to bacterial meningoencephalitis. The brain parenchyma in this condition will show
a.
Caseous necrosis
b.
Fat necrosis
c.
Fibrinoid necrosis
d.
Liquefactive necrosis=
e.
Coagulative necrosis
d.
Liquefactive necrosis=
What is the central dogma of genetics?
a.
mRNA–>DNA–>protein
b.
DNA–>protein–>mRNA
c.
DNA–>mRNA–>protein
d.
protein–>RNA–>DNA
e.
RNA–>DNA–>protein
c.
DNA–>mRNA–>protein
The multinucleate cell found in TB granuloma is known as
a.
Reed Sternberg giant cell
b.
Langhans giant cell
c.
Popcorn giant cell
d.
Langerhans giant cell
b.
Langhans giant cell
What is the name for a neuron with more than two branches arising from the cell body?
a.
Multipolar neuron
b.
Pseudounipolar neuron
c.
Unipolar neuron
d.
Bipolar neuron
a.
Multipolar neuron
Which of the following base pairing events results in the formation of the strongest bond?
a.
Adenine bound to thymine
b.
Cytosine bound to guanine
c.
Cytosine bound to cytosine
d.
Adenine bound to adenine
b.
Cytosine bound to guanine
A 20-year-old patient complains of recurrent respiratory infections and pustular rash. Doctor suggestsimmunogram test.
What is the marker for B lymphocytes in immunogram?
a.
CD 8+
b.
CD 4+
c.
CD 95+
d.
CD 22+
d.
CD 22+
The purified genome of certain viruses can enter a cell and elicit the production of progeny viruses (i.e.,the genome is infectious). Regarding these viruses, which one of the following statements is mostaccurate?
a.
They have a segmented genome
b.
They have a polymerase in the virion
c.
Their genome RNA is double-stranded
d.
Their genome RNA has positive polarity
d.
Their genome RNA has positive polarity
The demand for nucleotide biosynthesis is high during which stage of the cell cycle?
a.
G2
b.
G1
c.
M-phase
d.
S-phase
d.
S-phase
A 21-year-old female complains of joint pain, skin rash on her cheeks and bridge of nose and enlarged lymph nodes. After examination and laboratory tests she was diagnosed with Systemic Lupus Erythematosus (SLE, lupus).
What selection do T and B cells undergo to eliminate potential autoreactive cells?
a.
Overlap selection
b.
Neutral selection
c.
Positive selection
d.
Negative selection
d.
Negative selection
Which of the following allows for implantation of the blastocyst?
a.
Cleavage
b.
Hatching
c.
Compaction
d.
Karyogamy
b.
Hatching
A 45-year-old patient diagnosed to have acute appendicitis undergoes appendicectomy. Microscopic examination of a section from the appendix will show predominantly which type of inflammatory cells?
a.
Neutrophils
b.
Plasma cells
c.
Macrophages
d.
Lymphocytes
a.
Neutrophils
Which one of the following is a characteristic of the parasympathetic nervous system?
a.
Parasympathetic neurons innervating the respiratory system mediate bronchodilation.
b.
ACh is the neurotransmitter at autonomic ganglia.
c.
Postganglionic neurons are long and myelinated.
d.
Cell bodies for preganglionic neurons originate in the lumbar and thoracic regions of the spinalcord.
e.
NE is the neurotransmitter at parasympathetic ganglia.
b.
ACh is the neurotransmitter at autonomic ganglia.
What is meant by an extended spectrum penicillin?
a.
Bacteriocidal for both gram negative and gram positive bacteria
b.
Bacteriostatic for killing gram negative bacteria
c.
Bacteriocidal for killing gram positive bacteria
d.
Has an increased half-life in the body
a.
Bacteriocidal for both gram negative and gram positive bacteria
Which of the following occurs during embryogenesis week 2?
a.
Neurulation
b.
Fertilization
c.
Gastrulation
d.
Formation of a bilaminar disc (epiblast and hypoblast)
d.
Formation of a bilaminar disc (epiblast and hypoblast)
The plasma concentration of drug in a 40-year-old male would be increased by which of the following mechanisms?
a.
Renal secretion.
b.
Renal tubular reabsorption.
c.
Metabolic biotransformation.
d.
Binding to plasma proteins.
e.
Biliary excretion.
b.
Renal tubular reabsorption.
Non-invasive prenatal screening (NIPS) is a highly accurate screening test. What does it measure?
a.
The gestational age
b.
The presence of neural tube defect
c.
cfDNA of the fetus
d.
Amniotic fluid
e.
Maternal DNA
c.
cfDNA of the fetus
Which type of glial cell makes myelin in the peripheral nervous system?
a.
Astrocyte
b.
Schwann cell
c.
Microglial cell
d.
Oligodendrocyte
b.
Schwann cell
Which of the following is true concerning human skeletal muscle? It has
a.
Dyads
b.
Triads
c.
A centrally positioned nucleus
d.
Caveolae
e.
Intercalated disks
b.
Triads
All of the following are TRUE regarding apoptosis EXCEPT
a.
The nucleus of the cell undergoes pyknosis
b.
It is programmed cell death
c.
The apoptotic cell attracts inflammatory cells
d.
Apoptotic bodies are phagocytosed by macrophages
c.
The apoptotic cell attracts inflammatory cells
The maximum tensile strength of the injured tissue reached on wound healing compared to the normaltissue is
a.
30%
b.
100%
c.
50%
d.
80%
d.
80%
Historically, Murine monoclonal antibodies (MAB) were successfully used in patients but over time theireffectiveness was observed to decrease or even to be blocked.
What is the mechanism which leads to the decreased/blocked activity of murine MAB in patients?
a.
Production of HAMA
b.
Production of TNF
c.
Production of HACA
d.
Production of HAHA
a.
Production of HAMA
A woman who has a heterozygous genotype for the gene variant causing Phenylketonuria (PKU), mates with an unrelated man homozygous for the normal gene variant. What is the risk that their child will have PKU?
a.
100%
b.
25%
c.
0%
d.
50%
c.
0%
Activation of the parasympathetic nervous system results in which of the following responses?
a.
Renin secretion.
b.
Bronchoconstriction.
c.
An increase in heart rate.
d.
Vasoconstriction.
e.
Relaxation of the GI tract.
b.
Bronchoconstriction.
Which one of the following autonomic receptors are ligand-gated ion channels?
a.
Nicotinic
b.
Muscarinic
c.
β 1 -Adrenergic receptor
d.
α 1 -Adrenergic receptor
e.
α 2 -Adrenergic receptor
a.
Nicotinic
The time it takes for the body to decrease the levels of drug in the circulation by half is known as:
a.
Bioavailability.
b.
First pass.
c.
Clearance.
d.
Time of distribution.
e.
Half-life.
e.
Half-life.
DNA Polymerase can only add nucleotides in the 5’ to 3’ direction. To overcome this issue the cell uses the following mechanisms?
a.
Only replicates one strand
b.
Produces Okazaki fragments on the lagging strand
c.
Produces mRNA instead
d.
Can only synthesize one strand at a time, the leading strand followed by the lagging strand
b.
Produces Okazaki fragments on the lagging strand
For fatty acid synthesis to occur:
a.
Citrate synthase must be inactivated
b.
Pyruvate dehydrogenase must be inactivated
c.
Pyruvate carboxylase must be inactivated
d.
Lactate dehydrogenase must be activated
b.
Pyruvate dehydrogenase must be inactivated
What kind of spores contain many endospores within tissues?
a.
Arthroconidia
b.
Blastoconidia
c.
Conidia
d.
Spherules
d.
Spherules
While examining a family pedigree for a condition you notice that none of the affected males have sonsthat are affected. What is the inheritance pattern of the condition?
a.
Mitochondrial
b.
The phenomenon is due to imprinting
c.
Autosomal dominant
d.
The phenomenon is due to incomplete penetrance
e.
Autosomal recessive
a.
Mitochondrial
Chemotaxis refers to
a.
Migration of WBC’s between endothelial cells to the site of inflammation
b.
Increased random movement of WBC’s
c.
Migration of WBC’s through the basement membrane
d.
Unidirectional locomotion of WBC’s directed by chemo attractants
d.
Unidirectional locomotion of WBC’s directed by chemo attractants
Proteins are made up of:
a.
Glucose
b.
Amino acids
c.
Fatty acids
d.
Nucleic acids
b.
Amino acids
A pathologist notes fatty change in the liver biopsy of a patient with history of alcohol abuse. This finding is an example of
a.
Apoptosis
b.
Irreversible injury
c.
Reversible injury
c.
Reversible injury
Certain components of our immune system are characterized by two attributes: being able (1) torespond specifically to microbes and (2) to exhibit memory of having responded to a particular microbepreviously. Which one of the following has BOTH specificity and memory?
a.
Dendritic cells
b.
B cells
c.
Neutrophils
d.
Basophils
b.
B cells
Which of the following is a beta lactam antibiotic:
a.
Penicillin
b.
Tetracycline
c.
Macrolides
d.
Clindamycin
a.
Penicillin
Clostridium difficile is a gram-positive bacteria forming one of the large intestine microbiota. However,it can lead to a disease process after antibiotics use especially in elderly. This is mainly due to:
a.
Antibiotic treatment affect the normal population of large intestinal microbiota except for Clostridia due to its ability to form endospores
b.
Antibiotics help Clostridia to grow and multiply
c.
Exogenous infection
d.
Mutualistic relationship between the antibiotics and Clostridia difficile bacteria
a.
Antibiotic treatment affect the normal population of large intestinal microbiota except for Clostridia due to its ability to form endospores
An entire skeletal muscle is invested by a connective tissue element known as
a.
Endomysium
b.
Perimysium
c.
Epimysium
d.
External lamina
e.
Basement membrane
c.
Epimysium
A 32-year-old female was diagnosed with genital condylomas. The Doctor explained to the patient thatthis is infectious disease, induced by HPV (human papilloma virus) and can indicate a predisposal tocervical cancer.
What HPV types are most oncogenic?
a.
16 and 18
b.
43 and 71
c.
6 and 11
d.
44 and 54
a.
16 and 18
A 17-year-old male was admitted to the hospital with a soft tissue abscess. After surgery a tissue sample was sent to the laboratory for histological tests. Microscopy revealed infiltration of multilobed cells with segmented nuclei
What cells first react and migrate to the tissues during Antigen invasion?
a.
Eosinophiles
b.
Mast cells
c.
Basophiles
d.
Neutrophiles
d.
Neutrophiles
The initial step in the process of many bacterial infections is adherence of the organism to mucousmembranes. The bacterial component that mediates adherence is the:
a.
Plasmid
b.
Lipid A
c.
Peptidoglycan
d.
Pilus
e.
Nucleoid
d.
Pilus
A 31-year-old female with asthma was undergoing allergic skin testing. 15 minutes after exposure tothe allergens, her skin was seen to blister at the site of contact with allergen of birch.
What cells are responsible for histamine release and induction of a positive reaction in this patient?
a.
Dendritic cells
b.
Neutrophiles
c.
Mast cells
d.
Macrophages
c.
Mast cells
A 45-year-old patient diagnosed to have acute appendicitis undergoes appendicectomy. Gross examination of the appendix will show all of the following EXCEPT
a.
Fibrosis of the wall
b.
Congested blood vessels
c.
Edema of the wall
d.
Exudate on the serosa
a.
Fibrosis of the wall
Which of the following is a dimorphic fungi?
a.
Trichophyton
b.
Candida albicans
c.
Microsporum
d.
Blastomyces dermatitidis
d.
Blastomyces dermatitidis
The most common etiologic agent of gas gangrene is
a.
Streptococcus pyogenes
b.
Escherichia coli
c.
Clostridium perfringens
d.
Staphylococcus aureus
c.
Clostridium perfringens
A drug with a high volume of distribution would typically show:
a.
Low lipid solubility, high ionization, high protein binding
b.
Short half-life, high ionization, high protein binding
c.
High lipid solubility, low ionization, low protein binding
d.
High lipid solubility, high systemic clearance, high protein binding
c.
High lipid solubility, low ionization, low protein binding
Which of the following statements is CORRECT regarding autosomal recessive inheritance?
a.
Affected individuals are not seen in every generation
b.
Clinical expression results from heterozygous allele inheritance
c.
Male are more frequently affected than females
d.
Females are more frequently affected than males
a.
Affected individuals are not seen in every generation
Bacteria that cause nosocomial (hospital-acquired) infections often produce extracellular substancesthat allow them to stick firmly to medical devices, such as intravenous catheters. Which one of thefollowing is the name of this extracellular substance?
a.
Axial filament
b.
Flagella
c.
Endotoxin
d.
Porin
e.
Glycocalyx
e.
Glycocalyx
A 25-year-old male presents to the ER with complaints of productive cough and progressively increasing swelling in the neck for 3 months which has not subsided with multiple courses of antibiotics. He gives a history of low-grade fever, loss of appetite and weight loss. On examination, he has matted lymph nodes in the right supraclavicular region. Laboratory investigations show elevated ESR and CRP. Sputum AFB, Quantiferon Tb Gold and PCR for tuberculosis is positive. Microscopic examination of biopsy from the lymph node is given below. The multinucleate cells shown by the arrow head are derived from the fusion of
b.
Epithelioid cells
c.
Lymphocytes
d.
Neutrophils
e.
Basophils
b.
Epithelioid cells
Several bacteria that form spores are important human pathogens. Which one of the following is themost accurate statement about bacterial spores?
a.
They are produced by anaerobes only in the presence of oxygen.
b.
They are metabolically inactive yet can survive for years in that inactive state.
c.
They are killed by boiling for 15 minutes.
d.
They are formed primarily when the bacterium is exposed to antibiotics.
e.
They are produced primarily by gram-negative cocci.
b.
They are metabolically inactive yet can survive for years in that inactive state.
A 15-year-old patient is referred to your office by a teacher who is concerned about the patient’slearning abilities. After evaluating the patient, you diagnose mild mental retardation. Cytogeneticstudies of the patient’s buccal mucosal cells reveal a 47 XXY karyotype. Further evaluation is likely toreveal:
a.
Short stature, hypotonia, obesity
b.
Tall stature, gynecomastia, infertility
c.
Arachnodactyly, scoliosis, aortic root dilation
d.
Macroorchidism, large jaw and ears
e.
Short stature, broad chest, amenorrhea
b.
Tall stature, gynecomastia, infertility
You’re watching a television program that is discussing viruses called bacteriophages that can killbacteria. What’s the difference between viruses and bacteria? Which one of the following would be themost accurate statement to make?
a.
Viruses are prokaryotic, whereas bacteria are eukaryotic.
b.
Viruses do not have a nucleolus, whereas bacteria do.
c.
Viruses do not have ribosomes, whereas bacteria do.
d.
Viruses replicate by binary fission, whereas bacteria replicate by mitosis.
e.
Viruses do not have mitochondria, whereas bacteria do.
c.
Viruses do not have ribosomes, whereas bacteria do.
The protein coding region of a gene begins with:
a.
The poly-A tail
b.
The 5’ cap
c.
The first AUG or start codon encountered by the ribosome
d.
The 3’cap
c.
The first AUG or start codon encountered by the ribosome
Microscopic examination of section from the liver following embolism of the hepatic artery shows ghostcells and increased eosinophilia of hepatocytes. This is a characteristic microscopic feature of
a.
Coagulative necrosis
b.
Fat necrosis
c.
Gangrenous necrosis
d.
Caseous necrosis
e.
Liquefactive necrosis
a.
Coagulative necrosis
A 51-year-old male complains of recurrent Herpes simplex rash on his lips and genitals (up to 10 timesduring the year) and frequent respiratory viral infections. Doctor suspects acquired T cellimmunodeficiency, which was confirmed by low level of T lymphocytes in the immunogram.
What subtype of T lymphocytes is most likely to be decreased in this patient?
a.
T double-positive
b.
T cytotoxic
c.
T helper
d.
T reg
T cytotoxic
A 16-year-old patient presents with complaints of recurrent viral infections and herpes rash on the lips(15 times during a year). Doctor suggests immunogram test.
What is the marker for T lymphocytes in immunogram?
a.
CD 95+
b.
CD 3+
c.
CD 19+
d.
CD 22+
CD 3+
Drugs A, B, C, D, and E have therapeutic indices of 2, 5, 15, 20, and 50, respectively. Based on this, whichdrug has the lowest potential to have adverse or toxic effects?
a.
A
b.
B
c.
C
d.
D
e.
E
e.
E
A 25-year-old man experiences severe intolerance to certain medications. On 2 occasions, his reactionsto various drugs have necessitated hospital admission. His family pedigree with respect to this conditionis shown below, with the red arrow indicating his position within the family. Assume that this conditiondemonstrates complete penetrance and is rare in the general population. This condition most likelyexhibits which of the following inheritance patterns?
a.
X-linked recessive
b.
X-linked dominant
c.
Autosomal recessive
d.
Mitochondrial
e.
Autosomal dominant
a.
X-linked recessive
What is the common intermediate in the metabolism of carbohydrates, lipids and amino acids:
a.
Lactic acid
b.
Acyl-CoA
c.
Glucose 6 Phosphate
d.
Acetyl-CoA
d.
Acetyl-CoA
The percent of the unionized (HA) form of a weak acid with a pK a greater than 7 will be greatest inwhich body compartment?
a.
The duodenum with a pH of 5.5
b.
The cerebrospinal fluid (CSF) with a pH of 7.3
c.
The urine with a pH of 4-8
d.
The ileum and large intestine with a pH of 8
e.
The gastric juice with a pH of 2
e.
The gastric juice with a pH of 2
n studying a large number of families with a small deletion in a specific chromosome region, it is notedthat the disease phenotype is distinctly different when the deletion is inherited from the mother asopposed to the father. What is the most likely explanation?
a.
Imprinting
b.
Mitochondrial inheritance
c.
X-linked dominant inheritance
d.
X-linked recessive inheritance
e.
Sex-dependent penetrance
a.
Imprinting
Which of the following muscarinic receptors are associated with the heart?
a.
M1
b.
M2
c.
M3
d.
M4
b.
M2
The first reaction product of the TCA Cycle is:
a.
Citrate
b.
GTP
c.
Oxaloacetate
d.
Succinate
a.
Citrate
How many chromosomes are found in a healthy human oocyte?
Select one:
a.
92
b.
46
c.
23
d.
It varies between 23 and 46
c.
23
On the distal ends of the epiphysis is lined by articular cartilage, what type of cartilage is this classifiedas?
a.
Hyaline Cartilage
b.
Bony cartilage
c.
Fibrocartilage
d.
Elastic cartilage
a.
Hyaline Cartilage
An example of a ligand-gated ion channel is:
a.
Estrogen receptor
b.
Steroid receptor
c.
Insulin receptor
d.
GABAA receptor
d.
GABAA receptor
A single missense mutation in the gene coding for cystathionine beta-synthase causes a variety ofphenotypic manifestations including skeletal deformities, mental retardation and vascular thromboses.
This phenomenon is referred to as:
a.
Polyploidy
b.
Variable penetrance
c.
Segregation
d.
Imprinting
e.
Pleiotropy
e.
Pleiotropy
Which of the following is best described as an apocrine gland?
a.
Sweat gland
b.
Pancreas
c.
Mammary gland
d.
Salivary gland
c.
Mammary gland
A 58-year-old man who presents to the ER with complaints of heart burn and dysphagia undergoesesophagoscopy. Microscopic examination findings of the oesophageal biopsy given shows which typeof adaptive change in the lining epithelium?
a.
Anaplasia
b.
Hyperplasia
c.
Dysplasia
d.
Metaplasia
e.
Neoplasia
d.
Metaplasia
Which of the following represents a form of cell death involving pyknosis, chromatin condensation andfragmentation, as well as engulfment by resident phagocytes.
a.
Autophagic cell death
b.
Apoptosis
c.
Senescence
d.
Necrosis
b.
Apoptosis
Which of the following cells is derived from a hematopoietic cell precursor?
a.
Fibroblast
b.
Chondroblast
c.
Osteoclast
d.
Osteoblast
c.
Osteoclast
Substance X is present in the extracellular environment and is rapidly metabolized once it enters the
cells. We know that substance X crosses the cell surface membrane by simple diffusion.
What would you do to increase the number of substance X molecules entering the cell per second?
a. Decrease the surface area
b. Modify the chemical structure of substance X to make it lipophobic
c. Modify the chemical composition of the cell membrane to make it thinner
d. Block the enzyme responsible for the metabolism of substance X
c. Modify the chemical composition of the cell membrane to make it thinner
The beta-gamma subunit of a GPCR has which of the following actions?
a.
Increasing IP3 and DAG
b.
Activates protein lipase C
c.
Inhibits adenylyl cyclase
d.
Activate potassium channels
d.
Activate potassium channels
Influx of ________ into the sarcoplasm promotes muscle contraction.
a.
K+
b.
Na+
c.
Ca2+
d.
Mg2+
c.
Ca2+
Which of the following processes are involved in intracellular signaling cascades?
a.
Tyrosine phosphorylation
b.
Receptor association with and stimulation of G proteins
c.
Formation of second messengers, such as cAMP
d.
Mobilization of Ca 2+ from the endoplasmic reticulum
e.
All of the above
e.
All of the above
Which of the following statements is CORRECT about the phospholipids in the plasma membrane?
a.
The lipids and phosphates are hydrophobic
b.
The lipids are hydrophobic and the phosphates are hydrophilic
c.
The lipids and phosphates are hydrophilic
d.
The lipids are hydrophilic and phosphates are hydrophobic
b.
The lipids are hydrophobic and the phosphates are hydrophilic
The ion selectivity in an ion channel is largely determined by:
a.
Increase in intracellular calcium levels
b.
Amino acid residues in the pore spanning region
c.
Changes in membrane voltage
d.
G-beta-gamma subunit modulation
b.
Amino acid residues in the pore spanning region
Select the cell that is correctly matched to their function:
a.
Osteoblasts; bone resorption
b.
Monocytes; platelet aggregation
c.
Chondrocyte; cartilage ECM formation
d.
Fibroblasts; bone formation
c.
Chondrocyte; cartilage ECM formation
Factors that inhibit wound healing include all the following EXCEPT
a.
Presence of foreign body
b.
Immunosuppression
c.
Smoking
d.
Advanced age
e.
Vitamin C
e.
Vitamin C
Sickle cell anemia is caused by a missense mutation resulting in defective formation of a globin protein. In this condition, Glutamic acid is replaced by which of the following amino acids?
a.
Valine
b.
Lysine
c.
Arginine
d.
Phenylalanine
e.
Proline
a.
Valine
Which one of the following host defence processes is the MOST important in preventing the action ofexotoxins?
a.
Binding of cytokines to exotoxin-specific receptors inhibits the attachment of exotoxins
b.
Neutralization of exotoxins by antibody prevents binding to target cell membrane
c.
Lysis of exotoxins by perforins produced by cytotoxic T cells
d.
Degradation of exotoxins by the membrane attack complex of complement
b.
Neutralization of exotoxins by antibody prevents binding to target cell membrane
An Immunoglobulin that is the first class of antibody to appear, so its presence indicates an activeinfection rather than an infection that occurred in the past. It can fix complement, which is an importantdefense against many bacterial infections. It’s found in plasma as a pentamer.
a.
IgA
b.
IgD
c.
IgE
d.
IgM
e.
IgG
d.
IgM
A 15-year-old patient is referred to your office by a teacher who is concerned about the patient’slearning abilities. After evaluating the patient, you diagnose mild mental retardation. Cytogeneticstudies of the patient’s buccal mucosal cells reveal a 47 XXY karyotype. Further evaluation is likely toreveal:
a.
Tall stature, gynecomastia, infertility
b.
Arachnodactyly, scoliosis, aortic root dilation
c.
Short stature, hypotonia, obesity
d.
Short stature, broad chest, amenorrhea
e.
Macroorchidism, large jaw and ears
a.
Tall stature, gynecomastia, infertility
The proteins on the external surface of viruses serve several important functions. Regarding theseproteins, which one of the following statements is most accurate?
a.
They are the proteases that degrade cellular proteins leading to cell death.
b.
They are the antigens against which neutralizing antibodies are formed.
c.
They are the proteins that regulate viral transcription.
d.
They are the polymerases that synthesize viral messenger RNA.
They are the antigens against which neutralizing antibodies are formed.
A 36-year-old lady presents with a painful mass in the breast ten days after a fall. Examination of thebreast shows a hard lump. Microscopic examination of the excised lump will show
a.
Liquefactive necrosis
b.
Fibrinoid necrosis
c.
Fat necrosis
d.
Caseous necrosis
e.
Coagulative necrosis
c.
Fat necrosis
Regarding IgG, which one of the following is the most accurate?
a.
During the primary response, it is made in larger amounts than is IgM
b.
It is the only one of the five immunoglobulins that is transferred from mother to fetus inutero
c.
The ability of IgG to fix complement resides on the constant region of the light chain
d.
It is the most important antigen receptor on the surface of neutrophils
b.
It is the only one of the five immunoglobulins that is transferred from mother to fetus inutero
Regarding the structure and reproduction of fungi, which one of the following is most accurate?
a.
As most fungi are anaerobic, they should be cultured under anaerobic conditions in the clinicallaboratory
b.
Peptidoglycan is an important component of the cell wall of fungi
c.
Some fungi are dimorphic (i.e., they are yeasts at room temperature and molds at bodytemperature)
d.
The fungal cell membrane contains ergosterol, whereas the human cell membrane containscholesterol
e
Molds are fungi that grow as single cells and reproduce by budding
d.
The fungal cell membrane contains ergosterol, whereas the human cell membrane contains cholesterol
Stimulation of prejunctional or presynaptic α 2 -adrenergic receptors on postganglionic sympatheticneurons causes:
a.
Stimulation of NE release.
b.
Stimulation of Epi release.
c.
Inhibition of ACh release.
d.
Inhibition of NE release.
e.
Inhibition of Epi release
d.
Inhibition of NE release.
Homeostasis can be described as:
a.
a static state with no change from pre-set points
b.
the maintenance of a relatively stable internal environment
c.
a system to ensure bodily activities are kept to a minimum
d.
the body developing a disease state
b.
the maintenance of a relatively stable internal environment
A 25-year-old man experiences severe intolerance to certain medications. On 2 occasions, his reactionsto various drugs have necessitated hospital admission. His family pedigree with respect to this conditionis shown below, with the red arrow indicating his position within the family. Assume that this conditiondemonstrates complete penetrance and is rare in the general population. This condition most likelyexhibits which of the following inheritance patterns?
a.
X-linked recessive
b.
X-linked dominant
c.
Mitochondrial
d.
Autosomal dominant
e.
Autosomal recessive
a.
X-linked recessive
Which of the following is an example of an allosteric modulator?
a.
A drug that binds to a separate binding site as the agonist
b.
A drug that demonstrate irreversible binding
c.
A drug that competes for the same binding site as the agonist
d.
A drug that only blocks the action of another drug
a.
A drug that binds to a separate binding site as the agonist
Which organelle is essential for cells to be able to replicate?
a.
Mitochondria
b.
Smooth endoplasmic reticulum
c.
Ribosome
d.
Nucleus
d.
Nucleus
All Fungal organisms are?
a.
Prions
b.
Multicellular
c.
Prokaryotic
d.
Eukaryotic
d.
Eukaryotic
Cardiac muscle tissue is:
a.
Composed of tapered cells with interwoven filaments
b.
Surrounded by endomysium
c.
Under control of the somatic nervous system
d.
Branched and has intercalated disks
d.
Branched and has intercalated disks
Lysozyme in tears is an effective mechanism for preventing bacterial conjunctivitis. Which one of thefollowing bacterial structures does lysozyme degrade?
a.
Endotoxin
b.
Pilus
c.
Plasmid DNA
d.
Peptidoglycan
e.
Nucleoid DNA
d.
Peptidoglycan
The incidence of Duchenne muscular dystrophy in North America is about 1/3,000 males. Based on this,what is the gene frequency of this X-linked recessive mutation?
a.
1/9,000
b.
1/3,000
c.
1/6,000
d.
2/3,000
e.
(1/3,000)2
b.
1/3,000
Because males have only a single X chromosome, each affected male has one copy of the disease-causing recessive mutation. Thus, the incidence of an X-linked recessive disease in the male portion of apopulation is a direct estimate of the gene frequency in the population.
The correct answer is:
1/3,000
Which of the following techniques involves the application of distinct DNA sequences resulting in manyidentical copies sufficient for analysis?
a.
Northern blot
b.
Western blot
c.
Polymerase chain reaction (PCR)
d.
Southern blot
e.
Dot blot
c.
Polymerase chain reaction (PCR)
Enzymes work by
a.
increasing the spontaneity of the reaction
b.
increasing the activation energy
c.
decreasing the activation energy
d.
slowing the rate of the reaction
c.
decreasing the activation energy
32-year-old female presents to the ER complaining of pain and swelling in her lower extremities fortwo days, more severe in her right knee. The patient denies any history of recent or past trauma to thatregion. She further added that she had previously experienced similar pain in her elbows and ankles.Laboratory tests revealed leukocytosis and elevated ESR (erythrocyte sedimentation rate). Furthertesting revealed a positive throat culture for group A streptococcus and elevated titers ofantistreptolysin O (ASO).
What is the most probable trigger for development of the pathology in this patient?
a.
Genetic factors
b.
Breakdown of central tolerance
c.
Molecular mimicry
d.
Hyperproduction of Treg
c.
Molecular mimicry
Non-caseating granulomas are seen in all the following EXCEPT
a.
Tuberculosis
b.
Hodgkin lymphoma
c.
Crohn disease
d.
Sarcoidosis
a.
Tuberculosis
The sequence of cellular events in acute inflammation is
a.
Margination, rolling, transmigration, firm adhesion, chemotaxis, phagocytosis
b.
Margination, rolling, firm adhesion, chemotaxis, transmigration, phagocytosis
c.
Margination, rolling, firm adhesion, transmigration, chemotaxis, phagocytosis
d.
Margination, firm adhesion, rolling, transmigration, chemotaxis, phagocytosis
c.
Margination, rolling, firm adhesion, transmigration, chemotaxis, phagocytosis
A 34-year-old female complains of fatigue, tiredness, increased sensitivity to cold and most recently,hair loss. During examination the Doctor notices she has a pale skin and puffy face. The Doctor alsonoticed an enlarged thyroid gland and suspects Hashimoto’s thyroiditis (autoimmune disease)complicated with hypothyroidism.
What cells of the immune system prevent the development of autoimmune pathologies in a healthyperson?
a.
T double-positive
b.
T reg
c.
T cytotoxic
d.
T helper
b.
T reg
A 50-year-old man who presents to the ER with complaints of chest pain for one day is diagnosed tohave a myocardial infarct. He dies before intervention. Microscopic examination of the infarct will show
a.
Caseous necrosis of cardiac myocytes with plasma cell infiltrate
b.
Coagulative necrosis of cardiac myocytes with neutrophil infiltrate
c.
Dense fibrous scar
d.
Liquefactive necrosis of cardiac myocytes with lymphocyte infiltrate
e.
Fibrinoid necrosis of cardiac myocytes with macrophage infiltrate
b.
Coagulative necrosis of cardiac myocytes with neutrophil infiltrate
A patient enters the emergency department after she fell. The physician determined that she tore a tissue in her leg. The following photomicrograph represents the torn tissue. What did this patient tear?
A 65-year-old man is brought to the ER with complaints of chest pain radiating to the left arm. He is diagnosed to have myo cardialinfarction due to a block in the left anterior descending artery. A representative section from the myocardial infarct is shown in theimage. The infarct shows which type of necrosis?
a.
Gangrenous necrosis
b.
Caseous necrosis
c.
Liquefactive necrosis
d.
Fibrinoid necrosis
e.
Coagulative necrosis
e.
Coagulative necrosis
Non-invasive prenatal screening (NIPS) is a highly accurate screening test. What does it measure?
a.
Maternal DNA
b.
The presence of neural tube defect
c.
cfDNA of the fetus
d.
The gestational age
e.
Amniotic fluid
c.
cfDNA of the fetus
Regarding IgG, which one of the following is the most accurate?
a.
It is the only one of the five immunoglobulins that is transferred from mother to fetus in utero
b.
During the primary response, it is made in larger amounts than is IgM
c.
It is the most important antigen receptor on the surface of neutrophils
d.
The ability of IgG to fix complement resides on the constant region of the light chain
a.
It is the only one of the five immunoglobulins that is transferred from mother to fetus in utero
When it comes to fungi, what kind of spores looks like asexual spores formed by a (joint)?
a.
Spherules
b.
Blastoconidia
c.
Conidia
d.
Arthroconidia
d.
Arthroconidia
to this antagonist can:
a.
Cause down regulation of the receptor
b.
Result in supersensitivity
c.
Desensitize the receptor
d.
Produce tachyphylaxis
b.
Result in supersensitivity
Activation of the parasympathetic nervous system results in which of the following responses?
a.
Relaxation of the GI tract.
b.
Renin secretion.
c.
Vasoconstriction.
d.
Bronchoconstriction.
e.
An increase in heart rate.
d.
Bronchoconstriction.
Diapedesis refers to
a.
Aggregation of platelets at the site of injury
b.
Migration of RBC’s through the basement membrane
c.
Migration of leukocytes through the vessel wall to the site of inflammation
c.
Migration of leukocytes through the vessel wall to the site of inflammation
Herpes simplex virus is an enveloped virus. Based on the characteristics you learned about enveloped viruses, which of the followingis true?
a.
The lipid component of the membrane will make more easily inactivated by lipid solvents and detergents
b.
It can dry out and retain its infectivity
c.
It can survive the GIT environment
d.
The virion structure consists only of proteins
a.
The lipid component of the membrane will make more easily inactivated by lipid solvents and detergents
A pathologist notes fatty change in the liver biopsy of a patient with history of alcohol abuse. This finding is an example of
a.
Reversible injury
b.
Apoptosis
c.
Irreversible injury
a.
Reversible injury
Local signalling between a signal releasing cell and a neighbouring cell is called
Select one:
a.
Endocytosis
b.
Hormonal communication
c.
Paracrine communication
d.
Endocrine communication
c.
Paracrine communication
What is the purpose of the serosal membranes?
a.
They are the precursor to the cardiovascular system.
b.
They reduce friction for moving tissues like the heart and lungs.
c.
They increase vasculogenesis and angiogenesis for nutrient and gas exchange.
d.
They increase the flow of fluid into the internal cavities.
b.
They reduce friction for moving tissues like the heart and lungs.
Several bacteria that form spores are important human pathogens. Which one of the following is the most accurate statement aboutbacterial spores?
a.
They are produced by anaerobes only in the presence of oxygen.
b.
They are metabolically inactive yet can survive for years in that inactive state.
c.
They are formed primarily when the bacterium is exposed to antibiotics.
d.
They are killed by boiling for 15 minutes.
e.
They are produced primarily by gram-negative cocci.
b.
They are metabolically inactive yet can survive for years in that inactive state.
Certain components of our immune system are characterized by two attributes: being able (1) to respond specifically to microbes and(2) to exhibit memory of having responded to a particular microbe previously. Which one of the following has BOTH specificity andmemory?
a.
Basophils
b.
Neutrophils
c.
Dendritic cells
d.
B cells
d.
B cells
Which of the following are true about sulfonamide/trimethoprim:
a.
Beta lactam inhibitor
b.
Narrow spectrum
c.
Works against gram positive only
d.
Works as antagonist to folic acid synthesis
d.
Works as antagonist to folic acid synthesis
Which organelle is essential for cells to be able to replicate?
a.
Mitochondria
b.
Nucleus
c.
Smooth endoplasmic reticulum
d.
Ribosome
b.
Nucleus
On the distal ends of the epiphysis is lined by articular cartilage, what type of cartilage is this classified as?
a.
Hyaline Cartilage
b.
Elastic cartilage
c.
Bony cartilage
d.
Fibrocartilage
a.
Hyaline Cartilage
You’re watching a television program that is discussing viruses called bacteriophages that can kill bacteria. What’s the differencebetween viruses and bacteria? Which one of the following would be the most accurate statement to make?
a.
Viruses do not have mitochondria, whereas bacteria do.
b.
Viruses do not have ribosomes, whereas bacteria do.
c.
Viruses are prokaryotic, whereas bacteria are eukaryotic.
d.
Viruses replicate by binary fission, whereas bacteria replicate by mitosis.
e.
Viruses do not have a nucleolus, whereas bacteria do.
b.
Viruses do not have ribosomes, whereas bacteria do.
A 31-year-old female with asthma was undergoing allergic skin testing. 15 minutes after exposure to the allergens, her skin was seento blister at the site of contact with allergen of birch.
What cells are responsible for histamine release and induction of a positive reaction in this patient?
a.
Neutrophiles
b.
Macrophages
c.
Dendritic cells
d.
Mast cells
d.
Mast cells
Stimulation of prejunctional or presynaptic α 2 -adrenergic receptors on postganglionic sympathetic neurons causes:
a.
Inhibition of NE release.
b.
Inhibition of Epi release
c.
Stimulation of NE release.
d.
Stimulation of Epi release.
e.
Inhibition of ACh release.
a.
Inhibition of NE release.
Which of the following allows for implantation of the blastocyst?
a.
Cleavage
b.
Hatching
c.
Karyogamy
d.
Compaction
b.
Hatching
A 45-year-old patient diagnosed to have acute appendicitis undergoes appendicectomy. Microscopic examination of a section from the appendix will show predominantly which type of inflammatory cells?
a.
Lymphocytes
b.
Macrophages
c.
Plasma cells
d.
Neutrophils
d.
Neutrophils
A single missense mutation in the gene coding for cystathionine beta-synthase causes a variety of phenotypic manifestations including skeletal deformities, mental retardation and vascular thromboses.
This phenomenon is referred to as:
a.
Pleiotropy
b.
Imprinting
c.
Variable penetrance
d.
Segregation
e.
Polyploidy
a.
Pleiotropy
Drugs can interact with enzymes in which of the following ways?
a.
Inhibitors of an enzymes
b.
False substrates
c.
Pro-drugs
d.
All of the above
d.
All of the above
Opsonization is the process by which:
a.
Bacteria are made more easily phagocytized
b.
Neutrophils migrate from the blood through the endothelium to reach the site of infection
c.
Chemokines attract neutrophils to the site of infection
d.
The alternate pathway of complement is activated
a.
Bacteria are made more easily phagocytized
Select the correct statement.
a.
In the case of the Na+/glucose transport, Na+ moves into the cell against its concentration gradient and glucose moves intothe cell against its concentration gradient
b.
In the case of the Na+/glucose transport, both Na+ and glucose move into the cell along their concentration gradients
c.
In the case of the Na+/glucose transport, Na+ moves into the cell along its concentration gradient whereas glucose moves out of the cell against its concentration gradient
d.
In the case of the Na+/glucose transport, Na+ moves into the cell along its concentration gradient and glucose moves into the cell against its concentration gradient
d.
In the case of the Na+/glucose transport, Na+ moves into the cell along its concentration gradient and glucose moves into the cell against its concentration gradient
A 34-year-old female complains of fatigue, tiredness, increased sensitivity to cold and most recently, hair loss. During examination theDoctor notices she has a pale skin and puffy face. The Doctor also noticed an enlarged thyroid gland and suspects Hashimoto’sthyroiditis (autoimmune disease) complicated with hypothyroidism.
What cells of the immune system prevent the development of autoimmune pathologies in a healthy person?
a.
T reg
b.
T cytotoxic
c.
T helper
d.
T double-positive
a.
T reg
Huntington’s disease is due to which of the following mutations?
a.
Missense mutation
b.
Nonsense mutation
c.
Chromosomal deletion
d.
Silent mutation
e.
Trinucleotide repeat
e.
Trinucleotide repeat
A man who is affected with hemophilia A (X-linked recessive) mates with a woman who is a heterozygous carrier of this disorder. What proportion of this couple’s daughters will be affected, and what proportion of the daughters will be heterozygous carriers?
a.
0%; 50%
b.
0%; 100%
c.
100%; 0%
d.
2/3; 1/3
e.
50%; 50%
e.
50%; 50%
Because the man transmits his X chromosome to all of his daughters, all of the daughters must carry at least one copy of themutation. The mother will transmit a mutation-carrying X chromosome half the time and a normal X chromosome half the time. Thus,half of the daughters will be heterozygous carriers, and half will be affected homozygotes, having received a mutation from bothparents.
The correct answer is:
50%; 50%
Microscopic examination of section from the liver following embolism of the hepatic artery shows ghost cells and increasedeosinophilia of hepatocytes. This is a characteristic microscopic feature of
a.
Fat necrosis
b.
Gangrenous necrosis
c.
Coagulative necrosis
d.
Liquefactive necrosis
e.
Caseous necrosis
c.
Coagulative necrosis
In a healthy patient, the most populous leukocytes are
a.
Basophils
b.
Neutrophils
c.
Monocytes
d.
Lymphocytes
e.
Eosinophils
b.
Neutrophils
The first reaction product of the TCA Cycle is:
a.
Oxaloacetate
b.
Succinate
c.
GTP
d.
Citrate
d.
Citrate
A woman who has a heterozygous genotype for the gene variant causing Phenylketonuria (PKU), mates with an unrelated manhomozygous for the normal gene variant. What is the risk that their child will have PKU?
a.
0%
b.
100%
c.
50%
d.
25%
a.
0%
Herpes simplex virus is an enveloped virus. Based on the characteristics you learned about enveloped viruses, which of the following is true?
a.
It can survive the GIT environment
b.
The lipid component of the membrane will make more easily inactivated by lipid solvents and detergents
c.
It can dry out and retain its infectivity
d.
The virion structure consists only of proteins
b.
The lipid component of the membrane will make more easily inactivated by lipid solvents and detergents
A patient enters the emergency department after she fell. The physician determined that she tore a tissue in her leg. The following photomicrograph represents the torn tissue. What did this patient tear?
a.
Ligamentum nuchae
b.
Dermis of the skin
c.
Epidermis of the skin
d.
Tendon
e.
Peripheral nerve bundle
d.
Tendon
A 22-year-old female has a history of recurrent herpes simplex rash on her lips over the last three years. She had treatment with antiviral medicines with minimal success. The doctor decided to add immunostimulatory medicine to increase internal antiviral immune factors.
Which cytokines play the main role in antiviral immunity?
a.
G-CSF
b.
TNF
c.
Type I IFNs
d.
Type II IFNs
Type I IFNs
Which one of the following sets of cells can present antigen to helper T cells?
a.
Macrophages and eosinophils
b.
Neutrophils and cytotoxic T cells
c.
B cells and dendritic cells
d.
B cells and cytotoxic T cells
c.
B cells and dendritic cells
In relation to the Na+/K+ pump, which of the following describe the type of transport?
a.
Facilitated diffusion
b.
Secondary active transport
c.
Primary active transport
d.
Antiport
c.
Primary active transport
Drugs can interact with enzymes in which of the following ways?
a.
Inhibitors of an enzymes
b.
False substrates
c.
Pro-drugs
d.
All of the above
d.
All of the above
A man who is affected with hemophilia A (X-linked recessive) mates with a woman who is a heterozygous carrier of this disorder. What proportion of this couple’s daughters will be affected, and what proportion of the daughters will be heterozygous carriers?
a.
50%; 50%
b.
0%; 100%
c.
100%; 0%
d.
2/3; 1/3
e.
0%; 50%
a.
50%; 50%
Because the man transmits his X chromosome to all of his daughters, all of the daughters must carry at least one copy of the mutation. The mother will transmit a mutation-carrying X chromosome half the time and a normal X chromosome half the time. Thus, half of the daughters will be heterozygous carriers, and half will be affected homozygotes, having received a mutation from both parents.
The correct answer is:
50%; 50%
Many viruses are highly specific regarding the type of cells they infect. Of the following, which one is the most important determinant of this specificity?
a.
The surface glycoprotein
b.
The viral mRNA
c.
The matrix protein
d.
The protease protein
e.
The polymerase in the virion
a.
The surface glycoprotein
Which one of the following contains DNA that is not surrounded by a nuclear membrane?
a.
Molds
b.
Bacteria
c.
Protozoa
d.
Yeasts
b.
Bacteria
Cells placed in an isotonic solution will
a.
Double in size but remain intact
b.
Lyse due to excessive size
c.
Remain the same size
d.
Shrink and crenate
c.
Remain the same size
Local signalling between a signal releasing cell and a neighbouring cell is called
Select one:
a.
Endocrine communication
b.
Paracrine communication
c.
Endocytosis
d.
Hormonal communication
b.
Paracrine communication
An in vitro experiment was performed that involved adding two different drugs to a solution bathing a strip of intestinal smooth muscle. Both drugs cause relaxation of the muscle but had very different EC 50 values. Based on this single piece of information, which of the following statements is most correct?
a.
Both drugs activate the same receptor in the muscle.
b.
The two drugs have different potencies in causing relaxation.
c.
Both drugs are directly acting agonists.
d.
The two drugs have similar chemical structures.
e.
The maximum relaxation caused by the two different drugs will be similar.
b.
The two drugs have different potencies in causing relaxation.
