AAMC
AAMC MCAT PRACTICE EXAM 1
QUESTIONS AND CORRECT ANSWER S
UPDATED
(2026/2027)
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 CORRECT ANSWER C) 51 D
The CORRECT 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.
1
AAMC MCAT
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CORRECT ANSWER D) the transition state changes the activation energy of the
reaction.
The CORRECT 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 CORRECT ANSWER C) Adding
concentrated HCl (aq)
The CORRECT 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 CORRECT ANSWER B) increases
V = IR
The CORRECT 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.
2
AAMC MCAT
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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.)
A) 0.7
B) 1.4
C) 2.1
D) 3.0 CORRECT ANSWER B) 1.4
n = c/v
The CORRECT 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 CORRECT ANSWER D) number of photons
emitted
The CORRECT 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.
3
AAMC MCAT
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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
C) 1.1 × 10-18 J
D) 4.0 × 10-19 J CORRECT ANSWER D) 4.0 × 10-19 J
The CORRECT 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% CORRECT ANSWER B) 6%
The CORRECT 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?
4
AAMC MCAT
AAMC MCAT PRACTICE EXAM 1
QUESTIONS AND CORRECT ANSWER S
UPDATED
(2026/2027)
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 CORRECT ANSWER C) 51 D
The CORRECT 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.
1
AAMC MCAT
,AAMC
CORRECT ANSWER D) the transition state changes the activation energy of the
reaction.
The CORRECT 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 CORRECT ANSWER C) Adding
concentrated HCl (aq)
The CORRECT 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 CORRECT ANSWER B) increases
V = IR
The CORRECT 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.
2
AAMC MCAT
,AAMC
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.)
A) 0.7
B) 1.4
C) 2.1
D) 3.0 CORRECT ANSWER B) 1.4
n = c/v
The CORRECT 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 CORRECT ANSWER D) number of photons
emitted
The CORRECT 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.
3
AAMC MCAT
, AAMC
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
C) 1.1 × 10-18 J
D) 4.0 × 10-19 J CORRECT ANSWER D) 4.0 × 10-19 J
The CORRECT 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% CORRECT ANSWER B) 6%
The CORRECT 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?
4
AAMC MCAT
