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Exam Code: MCAT
Exam Questions: 815
Medical College Admission Test: Verbal Reasoning, Biological Sciences, Physical Sciences, Writing Sample
Updated: 13 Jul, 2026
Question 1

The Russia which emerged from the terrible civil war after the 1917 Revolution was far from the Bolsheviks’
original ideal of a non-exploitative society governed by workers and peasants. By 1921, the regime was
weakened by widespread famine, persistent peasant revolts, a collapse of industrial production stemming from
the civil war, and the consequent dispersal of the industrial working class – the Bolsheviks’ original base of
support. To buy time for recovery, the government in 1921 introduced the New Economic Policy, which allowed
private trade in farm products (previously banned) and relied on a fixed grain tax instead of forced requisitions
to provide food for the cities. The value of the ruble was stabilized. Trade unions were again allowed to seek
higher wages and benefits, and even to strike. However, the Bolsheviks maintained a strict monopoly of power
by refusing to legalize other parties.
After the death of the Revolution’s undisputed leader, Lenin, in January 1924, disputes over the long-range
direction of policy led to an open struggle among the main Bolshevik leaders. Since open debate was still
possible within the Bolshevik Party in this period, several groups with differing programs emerged in the course
of this struggle.
The program supported by Nikolai Bukharin – a major ideological leader of the Bolsheviks with no power base
of his own – called for developing agriculture through good relations with wealthy peasants, or “kulaks.”
Bukharin favored gradual industrial development, or “advancing towards Socialism at a snail’s pace.” In foreign
affairs, Bukharin’s policy was to ally with non-Socialist regimes and movements that were favorable to Russia.
A faction led by Leon Trotsky, head of the Red Army and the most respected revolutionary leader after Lenin,
called for rapid industrialization and greater central planning of the economy, financed by a heavy tax on the
kulaks. Trotsky rejected the idea that a prosperous, human Socialist society could be built in Russia alone
(Stalin’s slogan of “Socialism in One Country”), and therefore called for continued efforts to promote workingclass revolutions abroad. As time went on, he became bitterly critical of the new privileged elite emerging within
both the Bolshevik Party and the Russian state.
Joseph Stalin, General Secretary of the Bolshevik Party, was initially considered a “center,” conciliating figure,
not clearly part of a faction. Stalin’s eventual supremacy was ensured by three successive struggles within the
party, and only during the last did his own program become clear.
First, in 1924-25, Stalin isolated Trotsky, allying for this purpose with Grigori Zinoviev and Lev Kamenev,
Bolshevik leaders better known than Stalin himself, whom Trotsky mistakenly considered his main rivals. Stalin
maneuvered Trotsky out of leadership of the Red Army, his main potential power base. Next, Stalin turned on
Zinoviev and Kamenev, using his powers as head of the Party organization to remove them from party
leadership in Leningrad and Moscow, their respective power bases. Trotsky, Zinoviev, and Kamenev then
belatedly formed the “Joint Opposition” (1926-27). With Bukharin’s help, Stalin easily outmaneuvered the
Opposition: Bukharin polemicized against Trotsky, while Stalin prevented the newspapers from printing
Trotsky’s replies, organized gangs of toughs to beat up his followers, and transferred his supporters to
administrative posts in remote regions. At the end of 1927, Stalin expelled Trotsky from the Bolshevik Party and
exiled him. (Later, in 1940, he had him murdered.) Zinoviev and Kamenev, meanwhile, recanted their views in
order to remain within the Party.
The final act now began. A move by kulaks to gain higher prices by holding grain off the market touched off a
campaign against them by Stalin. Bukharin protested, but with the tradition of Party democracy now all but
dead, Stalin had little trouble silencing Bukharin. Meanwhile, he began a campaign to force all peasants – not
just kulaks – onto state-controlled “collective farms,” and initiated a crash industrialization program during which
he deprived the trade unions of all rights and cut real wages by 50%. Out of the factional struggle in which he
emerged by 1933 as sole dictator of Russia, Stalin’s political program of building up heavy industry on the
backs of both worker and peasant emerged with full clarity.
The passage supports the idea that struggles within the Bolshevik Party were primarily:

Section: Verbal Reasoning 

Options :
Answer: B

Question 2

The bacterial cells and virus particle, both have: 


Section: Biological Sciences 

Options :
Answer: B

Question 3

Due to ever-increasing paranoia about the transmission of hepatitis and AIDS via blood transfusions and the
frequent difficulty of procuring matching blood donors for patients, researchers have been working at a feverish
pace to produce disease-free and easy-to-use blood substitutes. The difficulty most synthetic blood researches
have had is in formulating a substance that combines qualities of sterility, high capacity for carrying oxygen to
body tissues, and versatility within the human body. Three major substitute technologies have been developed
to date; each has certain advantages and shortcomings.
“Red blood,” the first of the blood substitute technologies, is derived from hemoglobin which has been recycled
from old, dead, or worn-out red blood cells and modified so that it can carry oxygen outside the red blood cell.
Hemoglobin, a complex protein, is the blood’s natural oxygen carrier and is attractive to scientists for use in
synthetic blood because of its oxygen-carrying capacity. However, hemoglobin can sometimes constitute a twofold threat to humans when it is extracted from the red blood cell and introduced to the body in its naked form.
First, hemoglobin molecules are rarely sterile and often remain contaminated by viruses to which they were
exposed in the cell. Second, naked hemoglobin is extremely dangerous to the kidneys, causing blood flow at
these organs to shut down and leading, ultimately, to renal failure. Additional problems arise from the fact that
hemoglobin is adapted to operate optimally within the intricate environment of the red blood cell. Stripped of the
protection of the cell, the hemoglobin molecule tends to suffer breakdown within several hours. Although
modification has produced more durable hemoglobin molecules which do not cause renal failure, undesired
side effects continue to plague patients and hinder the development of hemoglobin-based blood substitutes.
Another synthetic blood alternative, “white blood”, is dependent on laboratory synthesized chemicals called
perfluorocarbons (PFCs). Unlike blood, PFCs are clear oil like liquids, yet they are capable of absorbing
quantities of oxygen up to 50% of their volume, enough of an oxygen carrying potential for oxygen-dependent
organisms to survive submerged in the liquid for hours by “breathing” it. Although PFCs imitate real blood by
effectively absorbing oxygen, scientists are primarily interested in them as constituents of blood substitutes
because they are inherently safer to use than hemoglobin-based substitutes. PFCs do not interact with any
chemicals in the body and can be manufactured in near-perfect sterility. The primary pitfall of PFCs is in their
tendency to form globules in plasma that can block circulation. Dissolving PFCs in solution can mitigate
globulation; however, this procedure also seriously curtails the PFCs’ oxygen capacity.
The final and perhaps most ambitious attempt to form a blood substitute involves the synthesis of a modified
version of human hemoglobin by genetically-altered bacteria. Fortunately, this synthetic hemoglobin seems to
closely mimic the qualities of sterility, and durability outside the cellular environment, and the oxygen-carrying
efficiency of blood. Furthermore, researchers have found that if modified hemoglobin genes are added to
bacterial DNA, the bacteria will produce the desired product in copious quantities. This procedure is extremely
challenging, however, because it requires the isolation of the human gene for the production of hemoglobin,
and the modification of the gene to express a molecule that works without support from a living cell.
While all the above technologies have serious drawbacks and difficulties, work to perfect an ideal blood
substitute continues. Scientists hope that in the near future safe synthetic blood transfusions may ease blood
shortages and resolve the unavailability of various blood types.
It can be inferred from the passage that the difficulty of producing an ideal blood substitute is compounded by
all of the following EXCEPT:

Section: Verbal Reasoning 

Options :
Answer: A

Question 4

In the course of gathering data in an experiment, a researcher develops the following correlation matrix:
MCAT-part-3-page300-image1
Table 1 Correlation Matrix
Which of the following pairs of variables are most strongly correlated?

Section: Psychology and Sociology 

Options :
Answer: B

Question 5

Which of the following is equivalent to one Pascal of gas pressure?


Section: Physical Sciences 

Options :
Answer: C

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