MCAT Quiz
Questions: 16 · 10 minutes
1. Two heterozygous parents have genotypes Aa and Aa for an autosomal recessive condition. What is the probability that their next child will have genotype aa?
0%
25%
50%
75%
2. In a spontaneous galvanic cell, what is the direction of electron flow through the external circuit?
From the cathode to the anode, where reduction occurs
From the anode to the cathode
From the electrolyte toward the cathode only
From the salt bridge to both electrodes
3. A chemist has a basic amine and a neutral compound dissolved in an organic solvent. Which step would most effectively transfer the amine into an aqueous layer while leaving the neutral compound primarily in the organic layer?
Add aqueous sodium hydroxide to deprotonate the amine.
Add a drying agent to remove water from the organic layer.
Add dilute aqueous hydrochloric acid to protonate the amine.
Cool the mixture to reduce the amine's molecular mass.
4. Read the passage: “Public libraries are often defended as storehouses of books. Yet their greater value may be their adaptability: they provide internet access, meeting rooms, local archives, and guidance for people navigating unfamiliar information systems.” Which statement best expresses the passage's main claim?
Libraries are valuable only when they offer services unavailable online.
Printed books are becoming irrelevant to public institutions.
Local archives should replace internet access in libraries.
The value of public libraries extends beyond storing books because they adapt to varied community needs.
5. A buffer contains equal concentrations of a weak acid and its conjugate base. According to the Henderson–Hasselbalch equation, how does the buffer's pH compare with the acid's pKa?
The pH is twice the pKa.
The pH is below the pKa by one unit.
The pH is above the pKa by one unit.
The pH equals the pKa.
6. Researchers compare volunteers who regularly consume caffeine with volunteers who avoid it, then measure reaction time. The caffeine group also slept substantially less the night before testing. Why does this weaken a causal interpretation?
Sleep duration may confound the relationship between caffeine and reaction time.
Caffeine consumption is necessarily the dependent variable.
Reaction time cannot be measured as a quantitative variable.
Any difference between naturally occurring groups proves reverse causation.
7. Shortly after a carbohydrate-rich meal, which metabolic response is most likely in a healthy person?
Glucagon rises and stimulates hepatic glycogen breakdown.
Insulin rises and promotes glycogen synthesis.
Cortisol falls and immediately stops cellular respiration.
Epinephrine rises and promotes widespread lipolysis.
8. A person hyperventilates for several minutes, exhaling carbon dioxide faster than it is produced. What immediate change is expected in the blood?
Carbon dioxide increases and pH decreases.
Carbon dioxide increases and pH increases.
Carbon dioxide decreases and pH decreases.
Carbon dioxide decreases and pH increases.
9. An author argues that remote work consistently increases productivity because one technology company reported higher output after closing its offices. Which new evidence would most weaken the author's general conclusion?
A large multi-industry study finds productivity effects vary substantially by job type and home working conditions.
The company also reduced the number of meetings after closing its offices.
Some employees at the company preferred working from home.
The company measured output for six months rather than five months.
10. Two resistors are connected in parallel. How does their equivalent resistance compare with the individual resistances?
It equals the sum of the two resistances.
It is less than either individual resistance.
It falls between the two individual resistances.
It equals the larger individual resistance.
11. A person finds that the expectations of being a full-time student interfere with the expectations of being an employee. Which sociological concept best describes this tension?
Role strain within a single status
Group polarization after discussion
Cultural diffusion between social groups
Role conflict between different statuses
12. A fixed amount of ideal gas is kept at constant temperature. If its pressure doubles, what happens to its volume?
It decreases to one-half of its original value.
It remains unchanged.
It doubles.
It decreases to one-fourth of its original value.
13. A competitive inhibitor is added to an enzyme-catalyzed reaction. Which change is expected under standard Michaelis–Menten assumptions?
Vmax decreases, while the apparent Km remains unchanged.
The apparent Km decreases, while Vmax remains unchanged.
The apparent Km increases, while Vmax remains unchanged.
Both Vmax and the apparent Km decrease.
14. A survey finds a strong positive correlation between daily social media use and self-reported anxiety. Which conclusion is justified by this result alone?
Social media use directly causes anxiety.
Anxiety directly causes increased social media use.
The variables are associated, but the result alone does not establish causation.
Eliminating social media would eliminate anxiety in the sample.
15. A car emits an irritating alarm until the driver fastens the seat belt. The driver's increased seat-belt use is best described as which learning process?
Negative reinforcement, because fastening removes an unpleasant stimulus
Positive reinforcement, because fastening adds a rewarding stimulus
Positive punishment, because fastening adds an unpleasant consequence
Extinction, because the behavior is no longer followed by a consequence
16. A red blood cell is placed in a hypotonic solution. What will initially happen to the cell?
Solute will leave until the cell becomes hypertonic.
Water will leave the cell, causing it to shrink.
Water will enter the cell, causing it to swell.
There will be no net water movement because the membrane blocks water.