PCAT Online Practice Questions and Answers

Which of the following is involved in hearing?

A. microvilli

B. cilia

C. hair follicles

D. hair cells

Which of the following does NOT happen during inflammation?

A. release of histamine

B. an increase of local temperature

C. migration of leukocytes

D. constriction of blood vessels

The oxidation of NADH occurs in which of the following?

A. glycolysis

B. TCA cycle

C. ETC

D. photosynthesis

Darwin's idea that evolution occurs by the gradual accumulation of small changes can be summarized as:

A. Convergent evolution

B. Adaptive radiation

C. Punctuated equilibrium

D. Phyletic gradualism

E. Sympatric speciation

Which of the following organelles helps green plants synthesize organic compounds like starch in the presence of sunlight?

A. Mitochondria

B. Chloroplast

C. Ribosomes

D. Golgi body

What is the hybridization of the carbons in benzene?

A. s

B. sp

C. sp2

D. sp3

The distribution of electrons evenly in a molecule contributes to stability. This accounts for:

A. atomic mass

B. valence

C. resonance

D. electronegativity

Separation of compounds by distillation is more efficient when:

A. carried out under reduced pressure

B. more condensation-vaporization cycles occur

C. carried out quickly

D. the condenser is very cold

What is the oxidation state of each nickel on the reactant side of the following reaction?

2 NiO(OH) + Cd + 2 H2O ?gt; 2 Ni(OH)2 + Cd(OH)2

A. -2

B. -1

C. +1

D. +3

What is the oxidation number of nitrogen in NF3?

A. -3

B. 0

C. +2

D. +3

Which effect would result from increasing the molar mass of a gas?

A. An increase in temperature

B. An increase on pressure

C. An increase in volume

D. A decrease in the rate

Which of the following is found to be different in isotopes of the same chemical element?

A. Protons

B. Neutrons

C. Electrons

D. Atomic number

The primary seat of tubercular infection is generally in the upper part of the lung. The invading organisms settle on the surface here and cause a multiplication of the cells and an inflammatory exudate in a small area. With the continuous growth of the bacilli in the localized region, adjoining areas of the lung become affected, and there is further extension into the immediate vicinity by means of the lymphatics. Small nodules form and then coalesce to create a larger area. The body primarily defends itself with the formation of dense masses of cicatricial tissue, which function to wall off the affected area. This results in unfavorable growth conditions for the bacilli. This mode of defense, combined with the production of substances antagonistic to the toxins produced by the bacilli, is so efficacious that in the great majority of cases no further extension of the process takes place. In certain cases, however, the growth of the bacilli in the focus area is unchecked, then the surrounding tissue is killed and converted into a soft semi-fluid material; further extension then takes place. All parts of the enormous surface of the lungs are connected by a system of air tubes or bronchi, and as a result, the bacilli have favorable opportunity for distribution. This opportunity is facilitated by sudden movements of the air currents in the lung produced by coughing. The body's defense; however, can still keep pace with the attack, and even in an advanced stage, the infection can sometimes be permanently checked; in other cases, the check is temporary, the process of softening continues, and large cavities are produced by the destruction of the tissue. On the inner surface of these cavities there may be a rapid growth of bacilli. From the lungs, the bacilli are carried by the lymphatics to the lymph nodes at the root of the lungs, in which a similar process takes place; this, on the whole, is favorable, because further extension by this route is for a time blocked. The extension across surfaces continues and the abundant sputum, which is formed in the lungs and contains large numbers of bacilli, becomes the vehicle of transportation. The windpipe and larynx may become infected, as the back parts of each are more closely in contact with the sputum and are the parts most generally infected. A large part of the sputum is swallowed and infection of the intestine takes place with the lesions taking the form of large ulcers. From the intestinal ulcers there is further extension by means of the lymphatics to the large lymph nodes in the back of the abdominal cavity.

According to the passage, which of the following is true about tubercular infection?

A. It can be stopped in the lungs, but not once it attacks the rest of the body.

B. It can always be stopped before fatality.

C. It can be checked until it reaches the intestines, but not after.

D. It can sometimes be checked in an advanced stage, but not always.

Lead ?non-biodegradable, soft, malleable, as well as heat and corrosion resistant ?is environmentally omnipresent. Its known properties make it an ideal metal for automobiles, paint, smelting, ceramics, and plastics. Not many years ago, it was also utilized in the toy industry. Unfortunately, lead is toxic to humans. Humans neither need lead nor derive benefits from it. Although lead toxicity has been a global concern since the industrial revolution in the late 1800s, civilization has been unable to prevent or control it satisfactorily. Overall incidence of lead poisoning among American children has fallen from 4.4% in the early 1990s to 1.4% in 2004. In 2002, around 10 out of every 100,000 of adults had lead toxicity. Venous blood lead levels (BLLs) of 10 mcg/dL and 25 mcg/dL were considered toxic in children and adults, respectively. But, since any level of lead can cause toxicity, the CDC announced a new, lower reference value for children in June 2012: 5 mcg/dL. Infants and children absorb a higher fraction of lead than adults do when exposed, increasing their vulnerability. Approximately 450,000 American children have BLLs >5 mcg/dL. Consequently, lead poisoning is still a problem. Lead exposure can start with prenatal maternal-fetal transmission. Outside the womb, children may inhale (or eat) lead dust, often present in street debris, soil, and most frequently, aged house paint. Lead-based paint was phased out in the 1970s, lowering, but not eliminating, risk of exposure. Old pipes sometimes leach lead into drinking water. Lead hazards are disproportionately found in low-income housing. Adults rarely develop lead poisoning, but risk is increased for industrial workers who use or manufacture lead-based products. Health care providers use many tests to identify lead poisoning. In addition to the BLL, a blood smear may show basophilic stippling ribosomal clusters. Increased urinary aminolaevulinic acid concentrations are also reliable indicators. Plain film radiographs can reveal visible lead lines in patients' long bones. Astute clinicians sometimes diagnose lead poisoning after seeing a blue line along patients' gums (Burton's line) that forms when lead reacts with sulfur ions released by oral bacteria. Lead affects every organ system and causes an unpredictable variety of symptoms. The nervous system is most sensitive (centrally in children, peripherally in adults), but lead affects hematopoietic, hepatic, and renal systems, producing serious disorders. Acute lead poisoning's classic symptoms include colic, encephalopathy, anemia, neuropathy, and Fanconi syndrome (abnormal glucose, phosphates, and amino acid excretion). Sometimes, classic signs and symptoms are absent, confusing the clinical picture.

Why are infants and children more vulnerable to lead poisoning?

A. They can absorb a greater fraction of lead than adults with the same exposure.

B. The CDC announced a new, lower reference value for children.

C. They can become exposed through prenatal maternal-fetal transmission.

D. Because 450,000 American children have BLLs >5 mcg/dL.

If number x is subtracted from 27, the result is -5. What is number x?

A. 22

B. 25

C. 32

D. 35