PACAT Practice Exam - Version 2

Question 1

Case:
Chlorine, potassium chloride, manganese (II) chloride, and water are to be produced by a graduate student through a reaction between potassium permanganate and hydrochloric acid. As part of their pre-lab checklist, the graduate student balances the chemical equation per the law of conservation of matter.

Question:
What coefficient is assigned to hydrochloric acid?

a. 1

b. 2

c. 4

d. 16

Answer 1

d. 16

Question 2

Case:
Ubiquitination is a post-translational modification used to regulate many processes: the cell cycle, cell death, protein function, protein degradation by the proteasome. Deubiquitinating enzymes remove ubiquitin from proteins, with implications in the same processes. Some viruses use deubiquitinating enzymes as a way to hijack the host cell.

Question:
What type of small molecule would combat such a virus?

a. Deubiquitinating enzyme activator

b. Deubiquitinating enzyme inhibitor

c. Proteasome activator

d. Proteasome inhibitor

Answer 2

b. Deubiquitinating enzyme inhibitor

Question 3

Case:
Down syndrome (trisomy 21) is an inherited genetic disorder associated with intellectual disability, characteristic facial appearance, and weak muscle tone (hypotonia) in infancy. It is a chromosomal disorder where affected children carry an extra copy of the 21st chromosome.

Question:
What is the genetic categorization of this disease?

a. Aneuploidy

b. Duplication

c. Euploidy

d. Insertion

Answer 3

a. Aneuploidy

Question 4

Case:
An epidemic of diarrheal disease caused by toxigenic Vibrio cholera affects a population.

Question:
What pathogen represents the source of disease?

a. Bacteriophage

b. Parasite

c. Prion

d. Virus

Answer 4

a. Bacteriophage

Question 5

Case:
A graduate student is tasked with making a sodium hydroxide (NaOH) solution.

Question:
What solvent is most appropriate?

a. C3H8O

b. C6H14

c. H2O

d. Pd

Answer 5

c. H2O

Question 6

Frequency Table

A B C D E F
1 0 1 2 2 0

What word matches this letter frequency table?

a. ADDED

b. BEADED

c. DECADE

d. DEFACED

Answer 6

c. DECADE

Question 7

Case:
DNA strands are wound around histones to form nucleosomes when forming chromosomes. Post-translational modification of histones affects the chromatin structure. One common post-translational histone modification is histone acetylation, where a positively charged lysine residue on the histone is acetylated and loses its charge.

Question:
How will histone acetylation affect chromatin structure and transcription?

a. Compact chromatin, decrease transcription

b. Compact chromatin, increase transcription

c. Relax chromatin, decrease transcription

d. Relax chromatin, increase transcription

Answer 7

d. Relax chromatin, increase transcription

Question 8

Pyruvate formed through the glycolytic pathway is transported to the mitochondrial matrix during the second stage of aerobic oxidation.

What is the end product of this oxidation?

a. CO2

b. FADH2

c. NAD+

d. O2

Answer 8

a. CO2

Question 8

Case:
A gas travels through a porous structure with openings smaller than the mean free path of the particles of the gas.

Question:
The opening must be smaller than what parameter?

a. Diameter of the molecule

b. Distance between collisions

c. Knudsen number

d. Viscosity of the gas

Answer 8

b. Distance between collisions

Question 9

Case:
Neurofibromatosis type 1 (NF1) is a genetic disease that results in dark spots (cafe-au-lait spots) and tumors on nerves in the skin, brain, and other parts of the body. With each pregnancy, one affected parent (father or mother) will have offspring with a 50% chance of being affected by the disease.

Question:
What can be deduced about the pattern of inheritance for NF1?

a. Autosomal dominant

b. Autosomal recessive

c. X-linked dominant

d. X-linked recessive

Answer 9

a. Autosomal dominant

Question 10

Case:
The rate of a certain condition in the United States is 2% of adults over age 50. A sample of 200 people from this population is taken.

Question:
What is the mean proportion of the sampling distribution of adults over 50 with this condition?

a. 0.02

b. 0.04

c. 2

d. 4

Answer 10

a. 0.02

Question 10

A scatter plot shows a data sample of efficiency versus area. Refer to the image.

When the area decreases, does the efficiency generally increase or decrease?

a. Cannot be determined

b. Decrease

c. Increase

d. Stays the same

Answer 10

b. Decrease

Question 11

Case:
The structure of the fungal cell wall is simple and based on substances other than ones found in animals and plants, which aids production of antifungal medications that are not toxic to mammals.

Question:
Which cell wall component is useful for this targeting?

a. Chitin

b. D-amino acids

c. Peptidoglycan

d. Protomers

Answer 11

a. Chitin

Question 12

The overall process of transcription is similar in prokaryotes and eukaryotes, but there are fundamental differences.

Which characteristic of transcription is unique to eukaryotes?

a. Lack of post-transcriptional modification

b. Presence of 3 types of RNA polymerase

c. Simple initiation machinery

d. Transcription and translation as a continuous process

Answer 12

b. Presence of 3 types of RNA polymerase

Question 13

Case:
A state of hypokalemia is increasing the ionic concentration gradient of a cardiac myocyte.

Question:
What additional factor favors potassium efflux under these conditions?

a. Depolarization

b. Insulation

c. Permeability

d. Resistance

Answer 13

c. Permeability

Question 14

T4 lysozyme is an enzyme that cleaves peptidoglycan in bacterial cell walls. Its activity is pH-dependent, with highest activity when Asp20 is deprotonated and Glu11 is protonated.

If Asp20 has a pKa of 3.6 and Glu11 has a pKa of 5.4, at what pH would you expect the enzyme to be most active?

a. 2.5

b. 4.5

c. 5.5

d. 7.5

Answer 14

b. 4.5

Question 15

Case:
When a depolarization threshold is reached, a neuron channel for sodium opens, allowing an influx of sodium to enter the cell.

Question:
What is the most direct effector of this phenomenon?

a. Current

b. Induction

c. Potential

d. Resistance

Answer 15

c. Potential

Question 16

Case:
Programmed DNA double-strand breaks are occurring during meiosis.

Question:
What characteristic will be most heavily influenced?

a. Chromatin strength

b. DNA replication

c. Genetic diversity

d. Reduction division

Answer 16

c. Genetic diversity

Question 17

Case:
A graduate student is tasked with mixing two containers of gas. The first is 20 L of H2 at 0.8 atm, and the second is 15 L of O2 at 1 atm. Both containers are at standard temperature. Both gases are to be added to a container with a volume of 10 L.

Question:
Once mixed, what is the partial pressure of H2?

a. .8 atm

b. 1.33 atm

c. 1.59 atm

d. 1.8 atm

Answer 17

c. 1.59 atm

Question 18

The rate of diffusion of a solute across a semipermeable membrane can be affected by several factors.

What factor affects the kinetic energy level of the solute molecules, increasing or decreasing the rate of diffusion?

a. Concentration gradient

b. Mass of molecules

c. Surface area

d. Temperature

Answer 18

d. Temperature

Question 19

A team of psychologists assesses the effectiveness of two interventions on reducing alcohol consumption: 12-step programs and cognitive behavioral therapy. The psychologists randomly assign 200 patients addicted to alcohol to attend 12-step groups and 200 to attend cognitive behavioral therapy.

What term best describes the type of study the psychologists conducted?

a. Case study

b. Experiment

c. Observational study

d. Survey

Answer 19

b. Experiment

Question 20

Case:
One organism performs the processes of transcription and translation simultaneously. A second organism undergoes post-transcriptional transformation to protect newly synthesized RNA from the nucleus to the ribosome.

Question:
Where does transcription occur in the first organism?

a. Cytoplasm

b. Golgi apparatus

c. Lysosome

d. Nucleus

Answer 20

a. Cytoplasm

Question 21

Case:
A patient presents with flank pain and hematuria. On CT scan, the patient is found to have an obstructing renal calculus.

Question:
Where is the stone most likely lodged?

a. Crossing common iliac arteries

b. Crossing external iliac arteries

c. Crossing psoas muscle

d. Crossing renal arteries

Answer 21

a. Crossing common iliac arteries

Question 22

Case:
Operant conditioning uses positive and negative reinforcement and punishment to modify behavior.

Question:
What is an example of negative reinforcement?

a. A child is placed in timeout for misbehaving.

b. An adolescent is given extra chores after missing curfew.

c. An alarm sounds in a car until the seatbelts are fastened.

d. An employee earns a bonus for performance at work.

Answer 22

c. An alarm sounds in a car until the seatbelts are fastened.

Question 23

The central dogma of molecular biology describes the process by which genetic information turns into proteins.

What conversion occurs during the process of transcription?

a. DNA into RNA

b. Protein into amino acids

c. RNA into DNA

d. RNA into proteins

Answer 23

a. DNA into RNA

Question 24

A scientist examines the inheritance of the human leukocyte antigens complex and observes its en bloc inheritance pattern.

What factor is responsible for this pattern?

a. Epistasis

b. Polygenicity

c. Polymorphism

d. Proximity

Answer 24

d. Proximity

Question 25

The middle layer of the wall of a heart chamber generates force for a contraction to propel blood through the heart.

What is located within this layer?

a. Lymphatic vessels

b. Pericardial fluid

c. Purkinje fibers

d. Sinoatrial node

Answer 25

d. Sinoatrial node

Question 26

The flow of blood through the heart includes pumping deoxygenated blood returning from the body to the lungs for oxygenation.

What structures are involved in this component of cardiac blood flow?

a. Left atrium, pulmonary veins

b. Left ventricle, pulmonary veins

c. Right atrium, pulmonary artery

d. Right ventricle, pulmonary artery

Answer 26

d. Right ventricle, pulmonary artery

Question 27

Case:
A cartilaginous structure containing the helix, antihelix, tragus, and antitragus is in high contact with the external environment.

Question:
What depression do these demarcations lead to?

a. Acoustic meatus

b. Bony labyrinth

c. Epitympanic chamber

d. Membranous labyrinth

Answer 27

a. Acoustic meatus

Question 28

Case:
During sleep, multiple areas of the brain act in concert to control sleep-wake cycles.

Question:
How does the pineal gland affect this process?

a. Increases production of melatonin, regulating biological rhythms

b. Produces gamma-aminobutyric acid (GABA), inhibiting multiple arousal systems

c. Relaxes muscles related to body posture and limb movement

d. Relays information from the senses to the cerebral cortex

Answer 28

a. Increases production of melatonin, regulating biological rhythms

Question 29

Case:
Influenza is inoculated into the upper respiratory passage of a patient and replicates, spreading to the lower respiratory passage and causing inflammation. The patient experiences high fever, cough, and myalgia as a result of the immune reaction to the viral infection.

Question:
What can occur during the course of this infection for this patient if they are in a high-risk group?

a. Optic neuritis

b. Postinfectious IBS

c. Pyelonephritis

d. Viral pneumonia

Answer 29

d. Viral pneumonia

Question 30

Case:
Within glycolysis, a series of ten enzymatic reactions convert glucose to pyruvate, and substrate-level phosphorylation leads to production of adenosine triphosphate (ATP).

Question:
What is the net quantity of ATP gained during this process?

a. 2

b. 4

c. 32

d. 36

Answer 30

a. 2

Question 31

Case:
A food bolus travels from the pharynx to the stomach.

Question:
What is anterior to the structure where this process is occurring?

a. Cricopharyngeus

b. Crural diaphragm

c. Hypopharynx

d. Trachea

Answer 31

d. Trachea

Question 32

Case:
Two long hydrocarbon chains joined to a polar head comprise the principal component of cell membranes.

Question:
What molecule does water interact with to form a biological membrane?

a. Carbohydrate

b. Nucleic acid

c. Phospholipid

d. Protein

Answer 32

c. Phospholipid

Question 33

Case:
A chemist performs a reaction with a ketone, sodium borohydride, and acetic acid.

Question:
What is an expected product?

a. Alcohol

b. Amine

c. Carboxylic acid

c. Ester

Answer 33

a. Alcohol

Question 34

A cylinder containing a gaseous compound is transported to a medical setting, where it will be attached to an anesthesia machine.

What property enables this utility?

a. Ability to be compressed under pressure

b. Ability to occupy less space than liquid counterparts

c. Ability to occupy less space than solid counterparts

d. Ability to resist expansion to fill a container

Answer 34

a. Ability to be compressed under pressure

Question 35

Case:
To remember a phone number, a person notes that the last 4 numbers match an important date.

Question:
Which type of memory encoding is this person using?

a. Acoustic encoding

b. Semantic encoding

c. Tactile encoding

d. Visual encoding

Answer 35

b. Semantic encoding

Question 36

Case:
A man visiting from a resource-limited country presents with transient pain of the wrists, ankles, and elbows. Physical examination reveals erythema marginatum, and an echocardiogram demonstrates carditis. The patient reports a sore throat 2-3 weeks ago.

Question:
What species is likely to be the source of disease?

a. Bacillus anthracis

b. Corynebacterium diphtheriae

c. Klebsiella pneumoniae

d. Streptococcus pyogenes

Answer 36

d. Streptococcus pyogenes

Question 37

Case:
A woman with breast cancer undergoes a radical mastectomy. Several weeks later, she presents unable to raise the arm above the horizontal plane. Physical examination reveals a protruding shoulder blade.

Question:
What was most likely damaged?

a. Lower trunk

b. Posterior cord

c. Roots C5-C7

d. Upper trunk

Answer 37

c. Roots C5-C7

Question 38

The American Psychiatric Association (APA) has developed a set of guidelines to define the concept of a psychological disorder, based on a specific theory.

What factor is consistent with the theoretical model that the APA’s definition is based on?

a. Atypical behavior

b. Functional impairment

c. Intrusive thoughts

d. Violating cultural norms

Answer 38

b. Functional impairment

Question 39

Mitosis and meiosis are forms of cell division, with the essential function of duplicating and separating the cell’s DNA content.

What characteristic is specific to the process of meiosis?

a. 46 chromosomes in produced cells

b. Genetically different daughter cells

c. Production of 2 identical daughter cells

d. Single-stage process

Answer 39

b. Genetically different daughter cells

Question 40

A B cell is stimulated by a pathogen, resulting in increased expression of cytokine receptors.

What primary interaction is caused by these molecules?

a. Excitatory response

b. Hypotensive response

c. Inflammatory response

d. Inhibitory response

Answer 40

c. Inflammatory response

Question 41

Case:
A provider prescribes a drug with a dose of 150 μg/kg body weight. Dimensional analysis is used to calculate the quantity of mg administered to a 160 lb patient with the understanding that 2.2 lb = 1 kg.

Question:
How many milligrams should be administered?

a. 10.5 mg

b. 10.91 mg

c. 15.25 mg

d. 52.8 mg

Answer 41

b. 10.91 mg

Question 42

What anucleate biconcave cells lack organelles?

a. Basophils

b. Eosinophils

c. Erythrocytes

d. Thrombocytes

Answer 42

c. Erythrocytes

Question 43

Which component of vasculature has the highest resistance?

a. Arteriole

b. Muscular artery

c. Elastic artery

d. Venule

Answer 43

a. Arteriole

Question 44

Case:
Air travels through the conducting zone of the respiratory system, reaches a bifurcation, and enters branches into the lungs.

Question:
What does air encounter as it flows through the left bifurcation, relative to the air that flows through the right path?

a. Equal division

b. Shorter size

c. Smaller diameter

d. Vertical alignment

Answer 44

c. Smaller diameter

Question 45

Between generations of a population, chance events result in changes in allele frequencies. What mechanism will lead to this population’s genetic diversity?

a. Allele flow

b. Genetic drift

c. Mutation

d. Selection

Answer 45

b. Genetic drift

Question 46

Case:
A pathogen evades host immune responses by switching to alternative variant surface glycoproteins as it multiplies in the host bloodstream.

Question:
What kind of pathogen exhibits this behavior?

a. Bacterium

b. Bacteriophage

c. Parasite

d. Prion

Answer 46

c. Parasite

Question 47

A patient’s tests reveal a deficiency in acid lipase A activity causing an accumulation of triglycerides and cholesteryl esters in the liver, spleen, and intestines.

Where is this enzyme normally found in the cell?

a. Endoplasmic reticulum

b. Golgi apparatus

c. Lysosome

d. Nucleus

Answer 47

c. Lysosome

Question 48

Case:
A 16-year-old boy is hit by a baseball—a direct blow to the side of his head—and loses consciousness. A CT scan of his head shows a fracture of one of his skull bones.

Question:
What bone is most likely affected by this injury?

a. Maxilla

b. Palatine

c. Parietal

d. Zygoma

Answer 48

c. Parietal

Question 49

Case:
A school-age child with history of declined vaccination presents with fever, headache, seizure, altered mental status, and skin vesicles. The attending provider orders a lumbar puncture, suspecting encephalitis.

Question:
What etiology is the most likely cause of these symptoms?

a. Bacteria

b. Fungi

c. Protozoa

d. Virus

Answer 49

d. Virus

Question 50

Case:
Two adults planning for pregnancy are concerned about a history of type 2 diabetes among many of the father’s family members. Type 2 diabetes is associated with multifactorial or polygenic inheritance.

Question:
What information about the risk for offspring should be shared with them?

a. Both parents must have a copy of the affected gene for the offspring to potentially have the disorder.

b. Increased risk is associated with environmental influences as well as shared genetic factors.

c. Inheriting one copy of the affected gene will be sufficient to cause the disorder in offspring.

d. The causative abnormality usually occurs randomly during the formation of a parent’s reproductive cells.

Answer 50

b. Increased risk is associated with environmental influences as well as shared genetic factors.

Question 51

Case:
A 27-year-old man (biological male) would like to know his risk for developing male pattern baldness. He has noted that his father, his father’s brother, and his father’s father have all developed baldness. His mother’s father is not bald.

Question:
If the gene that helps determine the presence or absence of male pattern baldness is X-linked recessive, whose phenotype should this patient observe to determine if he will develop male pattern baldness?

a. Father

b. Maternal grandfather

c. Paternal grandfather

d. Paternal uncle

Answer 51

b. Maternal grandfather

Question 51

Gametogenesis occurs through the process of meiosis, rather than mitosis.

What characteristic is associated with the process of meiosis?

a. Haploid or diploid mother cells

b. Prevention of chromosome crossing-over

c. Production of 2 daughter cells

d. Production of haploid cells

Answer 51

d. Production of haploid cells

Question 52

Stress is a dynamic process, representing an interaction between an external event and the physiological adaptations that occur in response.

What concept is specific to the response-based definition of stress?

a. Change is inherently stressful.

b. Life events are the source of stress.

c. Stress is a defensive mechanism.

d. Stress may be negative or positive.

Answer 52

c. Stress is a defensive mechanism.

Question 53

Case:
A patient develops secondary lymphedema due to trauma from a surgical procedure.

Question:
What condition may the patient experience?

a. Immune tolerance

b. Infertility

c. Malignancy

d. Rheumatoid arthritis

Answer 53

a. Immune tolerance

Question 54

Case:
A scientist synthesizes platinum-cobalt nanoparticles using the colloidal method.

Question:
For what industrial application can this product be used?

a. Catalyst

b. Culture media

c. Food additive

d. Tyndall effect

Answer 54

a. Catalyst

Question 55

Case:
A patient presents with colitis and dysenteric liver abscesses. Laboratory analysis reveals presence of sarcodines that use pseudopodia for motility.

Question:
What pathogen is responsible for these symptoms?

a. Entamoeba histolytica

b. Giardia lamblia

c. Toxoplasma gondii

d. Trypanosoma cruzi

Answer 55

a. Entamoeba histolytica

Question 56

Case:
The most superficial layer of the thorax wall contracts during inspiration.

Question:
What action will be executed?

a. Decrease the transverse diameter of the thorax

b. Depress the ribs

c. Elevate the lateral part of the ribs

d. Reduce the thoracic volume

Answer 56

c. Elevate the lateral part of the ribs

Question 56

Case:
A scientist examines the heat absorbed by a system under constant pressure.

Question:
What does this function depend on?

a. Integration path

b. Pressure during heating

c. Two thermodynamic properties

d. Usage of a catalyst

Answer 56

c. Two thermodynamic properties

Question 57

Case:
An electrical engineer measures 15.0 g of copper for an experiment.

Question:
How many atoms are in the sample?

a. 1.42 x 1022 atoms

b. 1.42 x 1023 atoms

c. 2.55 x 1023 atoms

d. 2.55 x 1024 atoms

Answer 57

b. 1.42 x 1023 atoms

Question 58

Case:
PIP2 is a component from membrane phospholipid hydrolyzed downstream of GPCRs. It serves as a precursor for IP3, which stimulates release of Ca2+ from intracellular stores.

Question:
What role does IP3 play in the release of Ca2+?

a. Ligand

b. Protein kinase

c. Regulatory protein

d. Secondary messenger

Answer 58

d. Secondary messenger

Question 59

The three domains of human development consist of specific characteristics, but they influence each other and are interdependent.

What development falls under the psychosocial domain?

a. Cooperation

b. Creative expression

c. Memory development

d. Planning

Answer 59

a. Cooperation

Question 60

Case:
The resting membrane potential of a neuron is depolarized, causing voltage-gated sodium channels to open. A current propagates along the membrane, opening additional voltage-gated sodium channels.

Question:
What restores concentration after this event?

a. Chemical gradient

b. Electrical gradient

c. Electrogenic pump

d. Membrane potential

Answer 60

c. Electrogenic pump

Question 61

Case:
Four cooperative ligaments form a triangle, connecting the tibia to the navicular, calcaneus, and talus.

Question:
Where is this source of stability?

a. Anterior

b. Medial

c. Lateral

d. Posterior

Answer 61

b. Medial

Question 62

Case:
A patient presents with difficulties flexing the thigh and extending the leg.

Question:
Damage to which of the following nerves is the cause of this patient’s deficits?

a. Common peroneal

b. Femoral

c. Obturator

d. Tibial

Answer 62

b. Femoral

Question 63

Case:
A chemist performs an experiment with an aldehyde and an oxidizing agent in the presence of an alcohol solvent.

Question:
What is an expected product?

a. Alcohol

b. Amine

c. Carboxylic acid

d. Ester

Answer 63

d. Ester

Question 64

Case:
A child physiologist is concerned about the number of times children with a certain condition wet the bed each month. They ask a sample of parents how many times their child (who has the condition) wet the bed during the month.

Question:
What is the probability of a child with this condition wetting the bed 0-6 times per month?

a. 0.06

b. 0.08

c. 0.14

d. 1

Answer 64

d. 1

Question 64

Case:
A sample of gas is introduced to one part of a closed container and its molecules disperse.

Question:
What has a direct relationship to the rate of this movement?

a. Density

b. Mass

c. Medium viscosity

d. Temperature

Answer 64

d. Temperature

Question 64

What is the function of the layer of lipopolysaccharides (LPS) in gram-negative bacteria?

a. Acts as an endotoxin

b. Contributes to cell wall thickness

c. Helps give shape

d. Provides cell wall rigidity

Answer 64

a. Acts as an endotoxin

Question 65

Case:
A chemistry professor demonstrated the kinetic-molecular description of liquids and gases by using two transparent pumps containing equal volumes of samples of a colored liquid and gas. The professor engaged the plunger to demonstrate compression of both substances.

Question:
What will the students observe?

a. Gas volume decreased.

b. Liquid mass decreased.

c. Mass and volume decreased for both liquid and gas.

d. Neither mass nor volume decreased for liquid or gas.

Answer 65

a. Gas volume decreased.

Question 65

Case:
A nursing home is experiencing an outbreak of pneumonia, with multiple patients experiencing difficulty breathing, cough, and fever. There is an additional subset of patients exhibiting fevers and fatigue with headaches. Urine and blood samples from patients, and water samples from the air conditioning cooling tower are sent to the microbiology lab for testing. The lab results confirm the presence of the same organism in the urine, blood and water samples.

Question:
What is the most likely organism?

a. Bordetella pertussis

b. Chlamydia pneumoniae

c. Legionella pneumophila

d. Respiratory syncytial virus

Answer 65

c. Legionella pneumophila

Question 66

Case:
A 52-year-old man with diabetes and hypertension presents with double vision in his right eye when his gaze is all the way to the right. Upon testing eye movements, the right eye does not move all the way to the right when testing lateral gaze.

Question:
What cranial nerve is affecting this patient’s vision?

a. Third cranial nerve

b. Fourth cranial nerve

c. Sixth cranial nerve

d. Seventh cranial nerve

Answer 66

c. Sixth cranial nerve

Question 66

Case:
A patient is having difficulties abducting the arm.

Question:
What makes up the affected zone?

a. First rib, scapula, and clavicle

b. Intertubercular groove of the humerus

c. Serratus anterior and thoracic wall

d. Subscapularis, teres major, and latissimus dorsi

Answer 66

a. First rib, scapula, and clavicle

Question 67

Case:
A botanist is examining the effects of various techniques on seed germination. The following samples were planted: 25 fresh Carica papaya seeds, 25 desiccated Carica papaya seeds, 25 rehydrated (1% agar/1 day) Carica papaya seeds, and 25 Carica papaya seeds treated by rehydration and heat shock (+10°C/5 hrs). Germination occurred for 70% of the Carica papaya seeds treated by rehydration and heat shock, 50% of the fresh Carica papaya seeds, 0% of the desiccated Carica papaya seeds, and 0% of the rehydrated Carica papaya seeds.

Question:
According to the scientific method, what next step would be suitable for the botanist after developing a conclusion?

a. Dissemination

b. Observation

c. Research

d. Testing

Answer 67

a. Dissemination

Question 68

Case:
A 32-year-old carpenter fell from the roof. The lateral longitudinal arch of his foot was flattened from fracture and displacement of the keystone for the arch.

Question:
Which bone of the foot is damaged?

a. Calcaneus bone

b. Cuboid bone

c. Head of the talus

d. Navicular bone

Answer 68

b. Cuboid bone

Question 68

Beta-2 adrenergic receptor (B2AR) is a G protein-coupled receptor. Beta-arrestin competitively blocks the coupling of G proteins to B2AR and causes the receptor to be internalized and degraded.

How would increasing the amount of beta-arrestin affect B2AR activity and downstream signaling?

a. Decrease B2AR activity and decrease downstream signaling

b. Decrease B2AR activity and increase downstream signaling

c. Increase B2AR activity and decrease downstream signaling

d. Increase B2AR activity and increase downstream signaling

Answer 68

a. Decrease B2AR activity and decrease downstream signaling

Question 68

A chemist attempts alcohol synthesis using a Grignard reagent.

What acts as the nucleophile?

a. Carbanion

b. Carbonyl

c. Hydronium ion

d. Magnesium halide

Answer 68

a. Carbanion

Question 69

Case:
A patient with a history of AIDS presents with flu-like symptoms after returning from travel to a subtropical region. Laboratory analysis reveals presence of protozoa that use an apical complex for motility.

Question:
Under what genus is the pathogen responsible for these symptoms classified?

a. Entamoeba

b. Leishmania

c. Plasmodium

d. Trichomonas

Answer 69

c. Plasmodium

Question 70

Case:
A 64-year-old man with a known clotting disorder and non-compliance with blood thinners presents to ED with severe abdominal pain for the last 2 hours since eating a large meal. He is found to have a thrombosis of his celiac trunk.

Question:
What artery is likely affected?

a. Ileocolic artery

b. Jejunal artery

c. Left colic artery

d. Splenic artery

Answer 70

d. Splenic artery

Question 70

Case:
White eye color mutation in Drosophila (fruit flies) replaces the normal brick-red eye color with white. When a male carrying the white eye mutation is crossed with a normal female, all the offspring show normal red eye color. When females from this offspring are crossed with normal males, the offspring are normal females and white-eye/red-eye males in a 1:1 ratio.

Question:
What could be the mode of inheritance for the white eye color mutation?

a. Autosomal dominant

b. Autosomal recessive

c. X-linked recessive

d. Y-linked recessive

Answer 70

c. X-linked recessive

Question 71

The pyruvate dehydrogenase complex synthesizes a carrier molecule used by a metabolic process that yields reduced coenzymes.

What does the carrier molecule deliver to this process?

a. Acetyl groups

b. GTP

c. Hydroxyl groups

d. NADH

Answer 71

a. Acetyl groups

Question 72

Case:
A professor graphed the results for an exam, then tells their students that the average was 78%. The grades resulted in a normal distribution with a standard deviation of 6.

Question:
What was the most frequent score in the class?

a. Most frequent score <72

b. Most frequent score = 72

c. Most frequent score = 78

d. Most frequent score >84

Answer 72

c. Most frequent score = 78

Question 72

Case:
A structure is bordered posteriorly by the pericardium, laterally by the pleural sacs, and anteriorly by the sternum, the left transversus thoracis, and the fifth, sixth, and seventh left costal cartilages.

Question:
What does this structure contain?

a. Esophagus

b. Internal thoracic branches

c. Superior vena cava

d. Thoracic duct

Answer 72

b. Internal thoracic branches

Question 73

A bacteriophage (virus) infects bacteria and moves short pieces of chromosomal DNA from one bacterial cell to another. Which type of horizontal gene transfer has occurred?

a. Conjugation

b. Transduction

c. Transfection

d. Transformation

Answer 73

b. Transduction

Question 74

Based on the scatter plot data, what is the best description of the correlation in the data between temperature and heating costs? Refer to the image.

a. High negative correlation

b. High positive correlation

c. Low negative correlation

d. Low positive correlation

Answer 74

a. High negative correlation

Question 75

Behavior can be affected by dispositional attributes and situational attributes.

What would have the greatest impact on behavior due to situational factors?

a. Attitude

b. Cultural influence

c. Personality traits

d. Religious beliefs

Answer 75

b. Cultural influence

Question 76

Case:
A patient is exposed to Rickettsia rickettsii and their adaptive immune response is assisting in resolving the infection.

Question:
What component of the adaptive immune response will be most active?

a. CD8+ T cells

b. Macrophages

c. Neutrophils

d. NK cells

Answer 76

a. CD8+ T cells

Question 77

Case:
A structure receives blood supplied by the inferior mesenteric artery.

Question:
What specific portion is supplied by branches of this artery?

a. Ascending colon

b. Cecum

c. Rectum

d. Sigmoid colon

Answer 77

d. Sigmoid colon

Question 77

An individual is consistently sympathetic, kind, helpful to others.

Which of the “big 5” personality traits does this behavior indicate?

a. Agreeableness

b. Conscientiousness

c. Extraversion

d. Openness

Answer 77

a. Agreeableness

Question 78

Case:
A 50-year-old woman is having chest pain; her cardiac enzymes and ECG suggest she may have had a myocardial infarction. The attending cardiologist is about to perform a cardiac catheterization to inject dye into her coronary arteries. He prepares her right inguinal region for insertion of the catheter into her femoral artery.

Question:
What are the landmarks for finding the location for this injection?

a. Halfway between the anterior inferior iliac spine and the pubic tubercle

b. Halfway between the anterior superior iliac spine and the pubic tubercle

c. Two-thirds way between the anterior inferior iliac spine and the pubic tubercle

d. Two-thirds way between the anterior superior iliac spine and the pubic tubercle

Answer 78

b. Halfway between the anterior superior iliac spine and the pubic tubercle

Question 79

Case:
A scientist creates a product with charged particles, suspended in dispersion medium, that scatter light.

Question:
What is expected of the product?

a. No chemical reaction occurs.

b. No settling occurs.

c. Precipitation occurs.

d. Solubilization occurs.

Answer 79

b. No settling occurs.

Question 80

Case:
After having a sandwich, a medical student feels full due to a division of the autonomic nervous system.

Question:
What location is an origin for the neurons located in this division of the autonomic nervous system?

a. Cervical

b. Craniosacral

c. Lumbar

d. Thoracic

Answer 80

b. Craniosacral

Question 81

Leber hereditary optic neuropathy (LHON) is an inherited form of vision loss. LHON has a mitochondrial mutation because the gene is located in the mitochondrial genome (mtDNA). Given this information about its genetics, what could be the mode of transmission of the disease?

a. Genomic imprinting

b. Maternal inheritance

c. Random mutation

d. Sex-influenced trait

Answer 81

b. Maternal inheritance

Question 81

Case:
A patient with a history of chronic obstructive pulmonary disease seeks treatment for COPD exacerbation, reporting more shortness of breath than usual. Analysis of sputum reveals a bacteria that targets cartilage oligomeric matrix protein (COMP).

Question:
What species is the most likely source of exacerbation?

a. Haemophilus influenzae

b. Moraxella catarrhalis

c. Pseudomonas aeruginosa

d. Streptococcus pneumoniae

Answer 81

b. Moraxella catarrhalis

Question 82

Case:
The liver can produce glucose through gluconeogenesis and store excess energy in the form of glycogen and lipids. Insulin is critical to regulating blood glucose concentrations and is released after a meal in healthy individuals.

Question:
How does insulin affect gluconeogenesis, glycogen storage, and lipid storage?

a. Inhibits gluconeogenesis, glycogen, and lipid storage.

b. Inhibits gluconeogenesis; stimulates glycogen and lipid storage.

c. Stimulates gluconeogenesis, glycogen, and lipid storage.

d. Stimulates gluconeogenesis; inhibits glycogen and lipid storage.

Answer 82

b. Inhibits gluconeogenesis; stimulates glycogen and lipid storage.

Question 83

A medical student is conducting research regarding the sequence of the chemical synaptic transmission pathway of acetylcholine. The student establishes that synthesis and storage of acetylcholine occur in the presynaptic terminal.

What will cause release of acetylcholine into the synaptic cleft?

a. Binding of acetylcholine to nicotinic receptors

b. Binding of acetylcholine to ligand-gated channels

c. Depolarization of the presynaptic terminal and calcium uptake

d. Diffusion of acetylcholine to the postsynaptic membrane

Answer 83

c. Depolarization of the presynaptic terminal and calcium uptake

Question 84

Case:
A specific muscle allows a person to chew without biting their cheeks.

Question:
What facial muscle aids in this process?

a. Buccinator

b. Lateral pterygoid

c. Masseter

d. Temporalis

Answer 84

a. Buccinator

Question 85

A structural component of the cellular membrane provides fluidity.

What is this component a precursor for?

a. Bilirubin

b. Testosterone

c. Tyrosine

d. Vitamin C

Answer 85

b. Testosterone

Question 86

Case:
Hemophilia is a bleeding disorder that shows delayed blood clotting. It occurs in two forms: hemophilia A or hemophilia B. Both forms are X-linked recessive traits.

Question:
Which children of a carrier mother and an unaffected father would be expected to have hemophilia?

a. All children are affected.

b. All children are unaffected.

c. Half of the female children are affected.

d. Half of the male children are affected.

Answer 86

d. Half of the male children are affected.

Question 87

Case:
Two friends are on a road trip. The friend driving is a black man, and the friend in the passenger seat is a white man. They have complied with all traffic laws but are pulled over by the police. The officer takes the white friend aside, asking if he needs help or if he is being held against his will.

Question:
What concept most directly influenced this officer’s actions?

a. Discrimination

b. Prejudice

c. Racism

d. Stereotypes

Answer 87

c. Racism

Question 88

A researcher exploring the relationship between myelination and conduction velocity. Which of the following is the result of increasing myelination of an axon?

a. Generation of an action potential

b. Hyperpolarization of an action potential

c. Increased conduction velocity

d. Increased fiber length

Answer 88

c. Increased conduction velocity

Question 89

A researcher is learning about action potentials in field mice. What observed quality would inform the student that these potentials are action potentials rather than graded potentials?

a. Absence of refractory period

b. All-or-none response to stimulus

c. Potential dissipating with distance from stimulus

d. Potential proportional to strength of stimulus

Answer 89

b. All-or-none response to stimulus

Question 90

Case:
A scientist examines a molecule with various functional groups, including groups with the formulas CnH2n, CnH2n+2, RCO2R′, and RCOR’.

Question:
Which functional group of this molecule is the least reactive?

a. Alkane

b. Alkene

c. Carbonyl

d. Ester

Answer 90

a. Alkane

Question 91

A scientist performs a reaction with barium hydroxide and sulfuric acid reactants. Barium sulfate and water are produced.

What is the representative chemical equation in net ionic format?

a. Ba(OH)2(aq) + H2SO4(aq) → BaSO4(s) + H2O(l)

b. Ba(OH)2(aq) + H2SO4(aq) → BaSO4(s) + 2H2O(l)

c. Ba2+(aq) + 2OH-(aq) +2H+(aq) + SO42-(aq) = BaSO4(s) + 2H2O(l)

d. Ba2+(aq) + SO42-(aq) = BaSO4(s) + 2H2O(l)

Answer 91

c. Ba2+(aq) + 2OH-(aq) +2H+(aq) + SO42-(aq) = BaSO4(s) + 2H2O(l)

Question 92

A provider orders 8 mg of a drug stocked as a 4 mg/mL solution.

How many grams are dispensed if 10 mL is injected?

a. .032

b. .04

c. 32

d. 40

Answer 92

b. .04

Question 93

Case:
An immunocompetent adult presents with fever and lymphocytosis. The attending provider suspects heterophile-negative mononucleosis.

Question:
Which etiological agent is most likely responsible?

a. Cytomegalovirus

b. Epstein-Barr virus

c. Human herpesvirus 6

d. Varicella zoster virus

Answer 93

a. Cytomegalovirus

Question 94

Case:
Deoxygenated blood enters the liver through a valveless, low-pressure, low-resistance circuit.

Question:
What vessel facilitates this entry?

a. Common iliac vein

b. Hepatic artery

c. Portal vein

d. Superior mesenteric artery

Answer 94

c. Portal vein

Question 95

An individual is very disciplined in terms of placing 10% of every paycheck in their savings account.

This behavior is associated with which level of Maslow’s hierarchy of needs?

a. Esteem/ego needs

b. Physiological needs

c. Security/safety needs

d. Social belonging

Answer 95

c. Security/safety needs

Question 96

Case:
A medical student prepares to draw blood from a patient. The attending reminds the student that the blood is drawn from a vein in the cubital fossa.

Question:
What is the relative position of the vein that will be used to draw blood?

a. Lateral to the brachioradialis muscle

b. Lateral to the median nerve

c. Medial to the biceps tendon

d. Medial to the pronator teres muscle

Answer 96

c. Medial to the biceps tendon

Question 97

Sections of DNA called common fragile sites (CFSs) tend to break easily, contributing to the formation of cancers. CFSs often form DNA secondary structures rather than the two DNA strands being held together strongly. Because of their structures, different nucleotides can form different numbers of hydrogen bonds. Guanine and cytosine form 3 hydrogen bonds. Adenine and thymine form 2 hydrogen bonds.

Which nucleotides can be predicted to constitute a large proportion of CFSs?

a. A and G

b. A and T

c. C and G

d. C and T

Answer 97

b. A and T

Question 98

Case:
Cyclic AMP is a secondary messenger when odorant receptors of the nose stimulate adenylyl cyclase to cause an increased concentration of intracellular cAMP, which opens sodium channels in the plasma membrane.

Question:
What type of receptor is affected by cAMP in this process?

a. Enzyme-linked receptor

b. G protein-coupled receptor

c. Ion channel receptor

d. Nuclear receptor

Answer 98

c. Ion channel receptor

Question 98

After consuming a meal, a patient begins to feel sleepy. What kind of receptor used by the nervous system is at work in this patient?

a. Acetylcholine

b. Alpha

c. Beta

d. Muscarinic

Answer 98

d. Muscarinic

Question 99

Case:
Many RNA molecules fold on themselves to form three-dimensional structures stabilized by hydrogen bonding between complementary bases.

Question:
What characteristic of RNA structure makes this possible?

a. RNA bases cannot form hydrogen bonds with each other.

b. RNA has phosphate groups in its backbone.

c. RNA is typically single-stranded.

d. RNA uses ribose instead of deoxyribose as its sugar.

Answer 99

c. RNA is typically single-stranded.

Question 100

What is the major cation in the extracellular fluid?

a. Bicarbonate

b. Chloride

c. Potassium

d. Sodium

Answer 100

d. Sodium

Question 100

Investigators want to determine if a DNA specimen from a crime scene belongs to a male or a female suspect.

What method can determine the answer?

a. Karyotyping

b. Polymerase chain reaction

c. Restriction enzyme digestion

d. Western blotting

Answer 100

b. Polymerase chain reaction

Question 100

Case:
Specific modifications of the tRNA are one way to regulate translation speed and accuracy. Uridine residues in the area of the tRNA that interacts with the mRNA when in the ribosome have been shown to be methylated, which enhances translation, especially when DNA is damaged.

Question:
Where are these uridine residues located on the tRNA?

a. Amino acid attachment site

b. Anti-codon stem-loop

c. D loop

d. T loop

Answer 100

b. Anti-codon stem-loop

Question 101

I-cell disease results from abnormal cleavage of mannose residues from glycoproteins, which ultimately results in coarse facial features, gingival hyperplasia, and clouded corneas.

What subcellular site deficit leads to this abnormal cleavage?

a. Endoplasmic reticulum

b. Golgi apparatus

c. Lysosome

d. Nucleus

Answer 101

b. Golgi apparatus

Question 101

Case:
A teenage girl presents with nausea, vomiting, fever, abdominal pain, and diarrhea. Analysis of stool sample indicates presence of fermentative Gram-negative rod-shaped bacteria.

Question:
What species is the most likely source of illness?

a. Campylobacter jejuni

b. Listeria monocytogenes

c. Salmonella enterica

d. Shigella sonnei

Answer 101

c. Salmonella enterica

Question 102

Case:
The GTP binding protein Kras is the most frequently mutated gene in pancreatic, lung, and colorectal cancer. The most common mutation is Kras.G12D, where the glycine at position 12 is replaced by an aspartic acid residue. The DNA sequence reveals a change from GGT to GAT at this position.

Question:
What kind of mutation is this?

a. Deletion

b. Insertion

c. Transition

d. Transversion

Answer 102

c. Transition