MCAT-TEST Online Practice Questions and Answers

Millenialism is, generally speaking, the religious belief that salvation and material benefits will be conferred upon a society in the near future as the result of some apocalyptic event. The term derives from the Latin word for 1,000; in early Christian theology, believers held that Christ would return and establish his kingdom on earth for a period of a thousand years.

Millenialist movements, Christian and non-Christian, have arisen at various points throughout history, usually in times of great crisis or social upheaval. In "nativistic" millenialist movements, a people threatened with cultural disintegration attempts to earn its salvation by rejecting foreign customs and values and returning to the "old ways." One such movement involving the Ghost Dance cults, named after the ceremonial dance which cult members performed in hope of salvation, flourished in the late 19th century among Indians of the western United States.

By the middle of the 19th century, western expansion and settlement by whites was seriously threatening Native American cultures. Mining, agriculture and ranching encroached on and destroyed many Indian land and food sources. Indian resistance led to a series of wars and massacres, culminating in the U.S. Government's policy of resettlement of Indians onto reservations which constituted a fraction of their former territorial base. Under these dire circumstances, a series of millenialist movements began among western tribes.

The first Ghost Dance cult arose in western Nevada around 1870. A Native American prophet named Wodziwob, a member of a Northern Paiute tribe, received the revelation of an imminent apocalypse which would destroy the white man, restore all dead Indians to life, and return to the Indians their lands, food supplies (such as the vanishing buffalo), and old way of life. The apocalypse was to be brought about with the help of a ceremonial dance and songs, and by strict adherence to a moral code which, oddly enough, strongly resembled Christian teaching. In the early 1870s, Wodziwob's Ghost Dance cult spread to several tribes in California and Oregon, but soon died out or was absorbed into other cults.

A second Ghost Dance cult, founded in January 1889, evolved as the result of a similar revelation. This time Wovoka -- another Northern Paiute Indian, whose father had been a disciple of Wodziwob -- received a vision during a solar eclipse in which he died, spoke to God, and was assigned the task of teaching the dance and the millennial message. With white civilization having pushed western tribes ever closer to the brink of cultural disintegration during the previous twenty years, the Ghost Dance movement spread rapidly this time, catching on among tribes from the Canadian border to Texas, and from the Missouri River to the Sierra Nevadas -- an area approximately one-third the size of the continental United States.

Wovoka's Ghost Dance doctrine forbade Indian violence against whites or other Indians; it also involved the wearing of "ghost shirts," which supposedly rendered the wearers invulnerable to the white man's bullets. In 1890, when the Ghost Dance spread to the Sioux Indians, both the ghost shirts and the movement itself were put to the test. Violent resistance to white domination had all but ended among the Sioux by the late 1880s, when government- ordered reductions in the size of their reservations infuriated the Sioux, and made them particularly responsive to the millenialist message of the Ghost Dance. As the Sioux organized themselves in the cult of the dance, an alarmed federal government resorted to armed intervention which ultimately led to the massacre of some 200 Sioux men, women and children at Wounded Knee, South Dakota in December of 1890. The ghost shirts had been worn to no avail, and Wounded Knee marked the end of the second Ghost Dance cult.

Which of the following tribes would probably NOT have taken part in the Ghost Dance cults?

A. The Potawatomi of Illinois

B. The Eastern Shoshoni of Wyoming

C. The Pawnee of Nebraska

D. The Southern Arapaho of Oklahoma

Agonistic behavior, or aggression, is exhibited by most of the more than three million species of animals on this planet. Animal behaviorists still disagree on a comprehensive definition of the term, but aggressive behavior can be loosely described as any action that harms an adversary or compels it to retreat. Aggression may serve many purposes, such as food gathering, establishing territory, and enforcing social hierarchy. In a general Darwinian sense, however, the purpose of aggressive behavior is to increase the individual animal's -- and thus, the species' -- chance of survival. Aggressive behavior may be directed at animals of other species, or it may be conspecific -- that is, directed at members of an animal's own species. One of the most common examples of conspecific aggression occurs in the establishment and maintenance of social hierarchies. In a hierarchy, social dominance is usually established according to physical superiority; the classic example is that of a pecking order among domestic fowl. The dominance hierarchy may be viewed as a means of social control that reduces the incidence of attack within a group. Once established, the hierarchy is rarely threatened by disputes because the inferior animal immediately submits when confronted by a superior. Two basic types of aggressive behavior are common to most species: attack and defensive threat. Each type involves a particular pattern of physiological and behavioral responses, which tends not to vary regardless of the stimulus that provokes it. For example, the pattern of attack behavior in cats involves a series of movements, such as stalking, biting, seizing with the forepaws and scratching with the hind legs, that changes very little regardless of the stimulus -- that is, regardless of who or what the cat is attacking. The cat's defensive threat response offers another set of closely linked physiological and behavioral patterns. The cardiovascular system begins to pump blood at a faster rate, in preparation for sudden physical activity. The eyes narrow and the ears flatten against the side of the cat's head for protection, and other vulnerable areas of the body such as the stomach and throat are similarly contracted. Growling or hissing noises and erect fur also signal defensive threat. As with the attack response, this pattern of responses is generated with little variation regardless of the nature of the stimulus. Are these aggressive patterns of attack and defensive threat innate, genetically programmed, or are they learned? The answer seems to be a combination of both. A mouse is helpless at birth, but by its 12th day of life can assume a defensive threat position by backing up on its hind legs. By the time it is one month old, the mouse begins to exhibit the attack response. Nonetheless, copious evidence suggests that animals learn and practice aggressive behavior; one need look no further than the sight of a kitten playing with a ball of string. All the elements of attack -- stalking, pouncing, biting and shaking -- are part of the game which prepares the kitten for more serious situations later in life.

Which of the following topics related to agonistic behavior is NOT explicitly addressed in the passage?

A. The physiological changes that accompany attack behavior in cats

B. The evolutionary purpose of aggression

C. Conspecific aggression that occurs in dominance hierarchies

D. The relationship between play and aggression

The mind, just like the body, has its needs. The needs of the body are the foundations of society; those of the mind are its amenities. While government and laws provide for the safety and well-being of men when they gather together, the sciences and the arts, which are less despotic but perhaps more powerful, spread garlands of flowers over the iron chains that bind them, stifle in them the sense for that original liberty for which they seem to have been born, cause them to love their own enslavement, and turn them into so-called "civilized people." Necessity raised thrones; the sciences and the arts have strengthened them. O earthly powers: cherish talents and protect those who cultivate them. O civilized people, cultivate them: you happy slaves owe to them that delicate and refined taste of which you are so proud, that gentleness of character and urbanity of manner which make relations among you so amiable and easy -- in other words, that semblance of all the virtues, none of which you actually possess... ...How pleasant it would be to live among us, if our external appearance were always a reflection of what is in our hearts, if decency were virtue, if our maxims served as our rules, and if true philosophy were inseparable from the title of philosopher! But so many qualities are seldom found together, and virtue hardly ever walks in such great pomp. Richness of adornment may be the mark of a man of taste, but a healthy, robust man is known by other signs: it is beneath the rustic clothes of a farmer, and not the gilt of a courtier, that strength and vigor of the body will be found. Ornamentation is just as foreign to virtue, which is the strength and vigor of the soul. The good man is an athlete who prefers to compete in the nude: he disdains all those vile ornaments which would hinder the use of his strength, ornaments which were for the most part invented only to hide some deformity. Before art had molded our manners and taught our passions to speak an affected language, our customs were rustic but natural, and differences in conduct revealed clearly differences in character. Human nature, basically, was no better, but men found security in being able to see through each other easily, and this advantage, which we no longer appreciate, spared them many vices. Now that more subtle refinements and more delicate taste have reduced the art of pleasing to set rules, a base and deceptive uniformity prevails in our behavior, and all minds seem to have been cast in the same mold. Incessantly politeness and propriety make demands on us, and incessantly we follow usage but never our own inclinations. We no longer dare to appear as we are, and under this perpetual constraint, the men who form this herd called society, when placed in the same circumstances, will all act similarly unless stronger motives direct them to do otherwise. Therefore we will never know well those with whom we deal, for to know our friends we will have to wait for some crises to arise -- which is to say that we will have to wait until it is too late, as it is for these very crises that it is essential to know one's friends well. What vice would not accompany this uncertainty? No more sincere friendships, no more genuine esteem, no more well-based confidence. Suspicion, offenses, fears, coldness, reserve, hatred and betrayal will constantly hide under the same false veil of politeness, under that much touted urbanity which we owe to the enlightenment of our times. The name of the Master of the Universe will no longer be profaned by swearing, but insulted by blasphemies that will not offend our scrupulous ears. Men will not boast of their own merits, but belittle those of others. An enemy will not be crudely insulted, but adroitly slandered. National hatreds will die, but so will patriotism. A dangerous skepticism will take the place of the scorning of ignorance. Some excesses will be forbidden, some vices dishonored, but others will be dignified with the name of virtues, and one must either have them or feign them. Let those who want to praise the sobriety of the sages of our time do so; as for me, I see in it only a refinement of intemperance that is as unworthy of my praise as their hypocritical simplicity.

According to the author's arguments, a society that prizes its sciences and arts will:

A. respect urbanity.

B. scorn ignorance.

C. foster sincere friendships.

D. embrace simplicity.

In 1972, Georges Ungar reported the discovery of a peptide that appeared to transfer learning. Ungar's claim was based on experiments in which rats placed in a chamber with specially designed dark and light regions were trained to avoid

the dark regions of the chamber. Following their training, the rats were killed and brain extracts were prepared. These brain extracts were injected into naive rats which were then observed to acquire the fear of darkness without training. Two

hypotheses were proposed to explain these remarkable results:

Hypothesis 1

Ungar concluded that the extracts contained some chemical that transmitted the learned fear of darkness to the naive rats. A fifteen amino-acid polypeptide was isolated from the brain extracts and sequenced. Ungar claimed that this peptide,

called scotophobin, was a chemical transmitter of learning. The peptide had the primary structure shown below:

C-ser-asp-asn-arg-gln-gln-gly-lys-ser-ala-arg-gln-glygly-tyr-N scotophobin

Hypothesis 2

Other researchers, who tested scotophobin but could not reproduce Ungar's results, argued that scotophobin did not transfer the learned fear of darkness. Instead, they suggested that scotophobin, which is structurally similar to ACTH and

vasopressin, acted to increase stress in the rats. Since stress increases sympathetic nervous activity, rats injected with scotophobin would become hyperactive and tend to spend less time in the dark regions of the experimental chamber.

They argued that such stress responses in the rats could be misinterpreted as a fear of darkness. Ungar's claim was further weakened by chemical analysis in which both the scotophobin extracts which Ungar had injected into the naive rats

and a sample of synthesized scotophobin peptide were subjected to SDS polyacrylamide gel electrophoresis, as shown in Figure 1.

Figure 1

Hydrolytic enzymes cleave polypeptides at specific amino acid residues. Which of the following hydrolytic enzymes could be used to cleave scotophobin into three fragments?

A. Trypsin only

B. Trypsin or clositripain only

C. Clositripain or chymotrypsin only

D. Clositripain or pepsin only

In 1972, Georges Ungar reported the discovery of a peptide that appeared to transfer learning. Ungar's claim was based on experiments in which rats placed in a chamber with specially designed dark and light regions were trained to avoid

the dark regions of the chamber. Following their training, the rats were killed and brain extracts were prepared. These brain extracts were injected into naive rats which were then observed to acquire the fear of darkness without training. Two

hypotheses were proposed to explain these remarkable results:

Hypothesis 1

Ungar concluded that the extracts contained some chemical that transmitted the learned fear of darkness to the naive rats. A fifteen amino-acid polypeptide was isolated from the brain extracts and sequenced. Ungar claimed that this peptide,

called scotophobin, was a chemical transmitter of learning. The peptide had the primary structure shown below:

C-ser-asp-asn-arg-gln-gln-gly-lys-ser-ala-arg-gln-glygly-tyr-N scotophobin

Hypothesis 2

Other researchers, who tested scotophobin but could not reproduce Ungar's results, argued that scotophobin did not transfer the learned fear of darkness. Instead, they suggested that scotophobin, which is structurally similar to ACTH and

vasopressin, acted to increase stress in the rats. Since stress increases sympathetic nervous activity, rats injected with scotophobin would become hyperactive and tend to spend less time in the dark regions of the experimental chamber.

They argued that such stress responses in the rats could be misinterpreted as a fear of darkness. Ungar's claim was further weakened by chemical analysis in which both the scotophobin extracts which Ungar had injected into the naive rats

and a sample of synthesized scotophobin peptide were subjected to SDS polyacrylamide gel electrophoresis, as shown in Figure 1.

Figure 1 In a follow-up experiment, researchers administered scotophobin to rats in order to examine its physiological effects. Which of the following observations of physiological effects in the rat would provide the best support for Hypothesis 2?

A. Increase in urine volume

B. The rat pupils dilate causing the rat to prefer darkness and avoid light

C. Increase in heart rate

D. Dilation of arterioles regulating blood flow to the digestive tract

The lead-acid battery, also called a lead storage battery, is the battery of choice for starting automobiles. It contains 6 cells connected in series, each composed of a lead oxide cathode "sandwiched" between 2 lead anodes. Insulating separators are placed between the electrodes to prevent internal short-circuits. Aqueous sulfuric acid is the electrolyte.

When the battery is being discharged, the following reaction takes place:

Reaction 1

The electrode reactions, both written as reductions, are shown in Table 1.

Table 1

Half-reaction

E?V)

PbO2(s) + SO42-(aq) + 4H+(aq) + 2ePbSO4(s) + 2H2O

PbSO4(s) + 2e-Pb(s) + SO42-(aq)

1.69

?.36

As a car operates, the battery is recharged by electricity produced by the car's alternator, an AC generator whose ultimate power source is the car's internal combustion engine. In spite of this, batteries eventually lose their power. The battery is said to be "dead" when Reaction 1 has proceeded completely to the right.

Often in cold weather the battery goes "dead". Thermodynamic data confirms that the voltage of most electrochemical cells decreases with decreasing temperature. If the battery is warmed to room temperature, it often recovers its ability to deliver normal power. The battery appeared "dead" because:

I) the resistance of the electrolyte had decreased. II) the viscosity of the electrolyte had increased. III) the viscosity of the electrolyte had decreased.

A. I only

B. II only

C. I and II only

D. I and III only

If iron sheet is dipped in a solution of zinc chloride and heated, then a layer of zinc is formed that protects iron from rusting. This process is called:

A. anodizing.

B. chrome plating.

C. galvanizing.

D. tin plating.

According to Boyle's Law, if a gas expands in volume from 5 L to 10 L and has an initial pressure of 1 atm, what is the final pressure?

A. 5 atm

B. 2 atm

C. 0.5 atm

D. 1 atm

A Hertzsprung - Russel diagram illustrates the different stages in a star's life cycle. Stars evolve along the main sequence, increasing in surface temperature. After the main sequence stage, a star cools and expands. Using the diagram, which stage would you expect to come directly after the main sequence?

A. giant

B. supernova

C. white dwarf

D. none of these

Arginine is one of the 20 most common natural amino acids. Most healthy people do not need to supplement with arginine because the body usually produces sufficient quantities. The pathway for arginine synthesis was studied using cells from a red bread mold. This natural form of arginine is illustrated below.

The red bread mold Neurospora crassa grows well on a cultural plate with "minimal" medium which is a fluid containing only a few simple sugars, inorganic salts, and vitamin. Neurospora that grows normally in nature (wild type) has enzymes that convert these simple substances into the amino acids necessary for growth. Mutating any one of the genes that makes an enzyme can produce a Neurospora strain that cannot grow on minimal medium. The mutant would only grow if the enzyme product were to be added as a supplement. On the other hand, if a "complete" medium is provided, containing all required amino acids, then Neurospora would grow, with or without mutation.

Figure 1 A synthesis pathway for the amino acid arginine. Each gene in italics in the diagram produces one enzyme necessary for the synthesis of this essential amino acid required for growth. Table 1 Growth response of mutant strains in "minimal" media with supplements (ornithine, citrulline, argininosuccinate, and arginine) as indicated. Strain growth is indicated by (+) and no strain growth is indicated by (-).

Experiments using the two mutant strains P and Q, reveal that strain P accumulates citrulline, but strain Q does not. Which of the following statements is most consistent with the data provided?

A. Strain Q has only one mutation.

B. Strain P has a mutation in argF only.

C. Strain P has mutations in argF, argG and argH.

D. Strain P has a mutation in argG only.