AAMC MCAT PRACTICE EXAM 1 QUESTIONS
AND ANSWERS UPDATED (2024/2025)
(VERIFIED ANSWERS)
A person whose eye has a lens-to-retina distance of 2.0 cm, can only clearly
see objects that are closer than 1.0 m away. What is the strength S of the
person's eye lens? (Note: Use the thin lens formula 1/O + 1/I = S)
A) -50 D
B) -10 D
C) 51 D
D) 55 D - ANS ✓C) 51 D
The answer to this question is C because the strength of the eye lens is
equal to the inverse of the focal length of the eye lens. Its numerical value is
given by (1 m)-1+(0.02 m)-1=1 D+50 D=51 D.
Which statement correctly describes how enzymes affect chemical
reactions? Stabilization of:
A) the substrate changes the free energy of the reaction.
B) the transition state changes the free energy of the reaction.
C) the substrate changes the activation energy of the reaction.
D) the transition state changes the activation energy of the reaction. - ANS
✓D) the transition state changes the activation energy of the reaction.
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The answer is D because the stabilization of the transition state, not the
substrate, provides binding energy that is used to lower the activation
energy.
Which of the following will decrease the percentage ionization of 1.0 M
acetic acid, CH3CO2H(aq)?*
A) Chlorinating the CH3 group
B) Diluting the solution
C) Adding concentrated HCl (aq)
D) Adding a drop of basic indicator - ANS ✓C) Adding concentrated HCl (aq)
The answer to this question is C because HCl is a strong acid that will
increase the amount of H+ in solution and thus decrease the percentage of
CH3CO2H that ionizes.
When the current in the micro-robot's circuit increases and the resistance
of the circuit remains constant, the voltage of the circuit:
A) decreases
B) increases
C) is constant
D) is zero - ANS ✓B) increases
V = IR
The answer to this question is B because according to Ohm's law, current is
equal to voltage divided by resistance. If current increases and resistance is
constant, then voltage increases as well.
Knowing that the speed of light in the vitreous humor is 2.1 × 108 m/s,
what is the index of refraction of the vitreous humor? (Note: The speed of
light in a vacuum is 3.0 × 108 m/s.)
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A) 0.7
B) 1.4
C) 2.1
D) 3.0 - ANS ✓B) 1.4
n = c/v
The answer to this question is B because the index of refraction of a
medium is equal to the ratio of the speed of light in vacuum to the speed of
light in the medium, thus it is equal to (3.0 x 108 m/s)/(2.1 x 108 m/s) =
1.4.
The intensity of the radiation emitted by the oxygen sensor is directly
proportional to the:
A) propagation speed of the radiation
B) wavelength of the radiation
C) polarization of photons emitted
D) number of photons emitted - ANS ✓D) number of photons emitted
The answer to this question is D because the energy of electromagnetic
radiation is directly proportional to the number of photons, and the
intensity of electromagnetic radiation is defined as energy emitted per unit
time. Thus, intensity is directly proportional to the number of photons
emitted.
What is the energy of the photons emitted by the LED at a frequency of 610
THz? (Note: h = 6.6 × 10-34 J·s)
A) 9.2 × 10-12 J
B) 1.6 × 10-16 J
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C) 1.1 × 10-18 J
D) 4.0 × 10-19 J - ANS ✓D) 4.0 × 10-19 J
The answer to this question is D because the energy of a photon of
frequency 610 THz is equal to 6.6 x 10-34 J•s x 610 x 1012 Hz = 4 x 10-19 J.
What percentage of standard atmospheric pressure is the pulse pressure of
a healthy adult?
The maximum and minimum blood pressures of a healthy adult are about
Ps = 120 mmHg and Pd = 75 mmHg.
Pp = Ps-Pd
A) 10%
B) 6%
C) 2%
D) 1% - ANS ✓B) 6%
The answer to this question is B because the pulse pressure in a healthy
adult is (120 − 75) mmHg = 45 mmHg, and so the percentage is 45
mmHg/760 mmHg = 6%.
What fraction of a O-15 sample decays in 10 min?
"The location of internal organs where changes in the calcium content
occur can be found by placing positron-emitting isotopes such as O-15
(with a half-life = 2 min) into the patient's bloodstream)
A) 1/8
B) 9/16
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