Admission Tests Admission Tests Certifications PCAT Questions & Answers

• Question 201:

  An electron pair donor is best classified as a:

  A. strong acid

  B. Bronsted-Lowry acid

  C. Lewis acid

  D. Lewis base

  Correct Answer: D

  By definition, a Lewis base is an electron pair donor. A Lewis acid, on the other hand, is an electron pair acceptor.

• Question 202:

  Which reaction can be spontaneous under favorable conditions?

  I. −∆H, +∆S

  II. −∆H, −∆S

  III.

  +∆H, −∆S

  A.

  I only

  B.

  II only

  C.

  I and III only

  D.

  I and II only

  Correct Answer: D

  Under favorable conditions, ∆H 0, a reaction will be spontaneous at any temperature. If one of the conditions is unfavorable with either ∆H > 0 or ∆S < 0, a reaction can be spontaneous if it satisfies ∆G < 0 using the standard-state free energy of reaction equation: ∆G = ∆H − T∆S. Roman numeral (I) satisfies both favorable conditions and will be spontaneous. Roman numeral (II) can be spontaneous if ∆H is sufficiently low. Roman numeral (III) can never be spontaneous.

• Question 203:

  The solubility of KCl in seawater would be ____ than the solubility of KCl in tap water.

  A. higher

  B. the same as

  C. lower

  D. KCl would completely insoluble in sea water as K cannot dissociate in water.

  Correct Answer: C

  Potassium chloride is a metal halide salt. And, while it dissolves readily in water, its solubility is lowered because of the common ions present in the seawater. This is otherwise known as the common ion effect.

• Question 204:

  Bile mainly helps in the digestion of:

  A. Fats

  B. Proteins

  C. Carbohydrates

  D. Bile pigments

  Correct Answer: A

  Bile (or gall) is a bitter, greenish-yellow alkaline fluid secreted by the liver of most vertebrates. It helps in the complete digestion of fats by reducing surface tension. It also activates the enzyme lipase. It serves as a good solvent for fats and fat-splitting enzymes. Bile also helps in absorption of carbohydrates, fats, fat soluble vitamins and proteins.

• Question 205:

  Which of the following lipids in a cell membrane acts as a selective barrier for controlling the exit and entry of substances into and out of the cell?

  A. Cholesterol

  B. Glycolipids

  C. Phospholipids

  D. Lipoproteins

  Correct Answer: C

  The primary type of lipids found in the cell membrane are phospholipids, cholesterol and glycolipids. Out of these, phospholipids play an important role in controlling the movement of substances into and out of the cell. In general, lipid soluble substances are allowed to move into the cell whereas water soluble molecules are restricted or not allowed to pass through the cell membrane.

• Question 206:

  Which of the following provides the necessary freedom for bones as well as protect joints from external injury and bones from dislocation?

  A. Cartilage

  B. Ligaments

  C. Tendons

  D. Muscles

  Correct Answer: B

  Ligaments are strong flexible white fibrous bands. They bind the articular surfaces of bones together. They provide necessary freedom for the bones as well as protect joints from external injury and bones from dislocation. Tendons are white bands which join muscles with bones while ligaments hold bones together at joints and are inelastic.

• Question 207:

  Which of the following polysaccharides is largely stored in the liver and muscles?

  A. Cellulose

  B. Starch

  C. Glycogen

  D. Inulin

  Correct Answer: C

  Glycogen is considered the principal storage form of glucose and is found mainly in the liver and muscle, with kidney and intestines adding minor storage sites. Glycogen is formed by the liver from glucose in the bloodstream and is stored in the liver. Glycogen is also produced by and stored in muscle cells; during short periods of strenuous activity, energy is released in the muscles by direct conversion of glycogen to lactic acid. During normal activity, energy is released by metabolic oxidation of glucose to lactic acid. Glycogenesis (formation of glycogen from glucose) and glycogenolysis (break down of glycogen into glucose) are two principal mechanisms by which blood glucose level has been maintained.

• Question 208:

  Which of the following nitrogen bases is present in RNA but absent in DNA?

  A. Cytosine

  B. Uracil

  C. Guanine

  D. Adenine

  Correct Answer: B

  RNA consists of ribose pentose sugar. Unlike DNA, it consists of only one polynucleotide chain. It also contains two purine and pyrimidine bases. Uracil (U) is the nitrogen base which is present in RNA but absent in DNA. Thus, RNA contains Adenine (A) and Guanine (G) as purine bases, and Cytosine (C) and Uracil (U) as pyrimidine bases.

• Question 209:

  Nitrogen fixing bacteria on root nodules of Leguminous plants are known as:

  A. Azobacteria

  B. Nanobacteria

  C. Rhizobium bacteria

  D. Mycobacteria

  Correct Answer: C

  Nitrogen fixing bacteria on root nodules of Leguminous plants are known as Rhizobium. They fix the atmospheric nitrogen and convert it into ammonia. The nitrogen fixing bacteria are also known as nitrifying bacteria.

  Azobacteria are present in the soil. They convert atmospheric nitrogen into nitrates and nitrites. In this way, they increase the fertility of the soil. These ammonium nitrates and nitrites are then absorbed by plants to obtain nitrogen.

• Question 210:

  In the process of Mitosis, if the number of chromosomes in the mother cell is designated as 2n, how many chromosomes will be present in each daughter cell?

  A. 2n

  B. n

  C. 4n

  D. 8n

  Correct Answer: A

  Cell division is a very complex process. There are two main types of cell division:

  1.

  Mitosis

  2.

  Meiosis

  1.

  Mitosis: In this type of cell division, chromosomes are equally distributed in each daughter cell. As a

  result, the number of chromosomes in the daughter cells is the same as that in the mother cell. It is also

  known as equational division. (e.g.

  Somatic cells division)

  2.

  Meiosis: In this type of cell division, chromosomes are divided in half of the original mother cells,

  therefore the daughter cells consist of half the number of chromosomes that are in the mother cell. (e.g.

  reproductive or sex cells division)