Test Prep OAT Online Practice Questions and Exam Preparation

Test Prep OAT Online Questions & Answers

• Question 161:

  Which of the following paracrine signaling molecules increases gastric acid production in the stomach?

  A. Somatostatin
  B. Prostaglandins
  C. Histamine
  D. GIP
  E. None of the above
  C. Histamine

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  Histamine induces gastric acid secretion in the stomach. Somatostatins inhibit gastric acid secretion, as does GIP.

• Question 162:

  Which of the following are not pyrimidines?

  A. Cytosine
  B. Thymine
  C. Uracil
  D. Guanine
  E. C and D
  D. Guanine

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  Uracil, Cytosine and Thymine are pyrimidines. Adenine and Guanine are purines.

• Question 163:

  Which is the correct order of classification, going from most broad to most specific?

  A. Phylum > Order > Class > Genus > Species
  B. Domain > Class > Order > Species > Genus
  C. Domain > Phylum > Class > Family > Species
  D. Phylum > Family > Class > Order > Genus
  E. Species > Genus > Family > Order > Class
  C. Domain > Phylum > Class > Family > Species

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  This is the most accurate order of classification.

  It is usually: Domain > Phylum > Class > Order > Family > Genus > Species

• Question 164:

  Which of the following functions in regulating and allowing chyme to pass from the stomach to the duodenum of the small intestine?

  A. Cardiac sphincter
  B. Pyloric sphincter
  C. Ileocecal sphincter
  D. Esophageal sphincter
  E. Sphincter of Oddi
  B. Pyloric sphincter

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  Pyloric sphincter is indeed the function that the question describes. Sphincter of Oddi functions in allowing digestive juices (bile) through the hepatopancreatic duct. Cardiac sphincter functions between the esophagus and the stomach, preventing stomach juice (acid) from coming up the esophagus. The Ileocecal sphincter borders the small and large intestine, preventing contents from the colon spilling back into the ileum (small intestine). The esophageal sphincter functions in opening to allow food from the mouth to enter the esophagus. It is very important to know and understand the functions of these main sphincters in the body.

• Question 165:

  Which of the following statements is FALSE regarding C3 and C4 photosynthesis?

  A. The CO2 is incorporated into a 3-carbon compound in C3.
  B. In C3, the CO2 is directly fed into the Calvin Cycle.
  C. In C3, RUBISCO is used to fix CO2.
  D. The C3 and C4 reactions are temporally separated.
  E. All of the above are true statements.
  E. All of the above are true statements.

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  All of the above are accurate statements.

• Question 166:

  In a classroom of 189 students, the ratio of boys to girls is 5 : 4. How many boys are there in the classroom?

  A. 38
  B. 84
  C. 105
  D. 120
  E. 155
  C. 105

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  The simplest way to approach these problems is to divide the total number of students (189) by the combined ‘parts’ (5 + 4 = 9). Thus 189 ÷ 9 = 21.

  Multiply 21 by the gender of interest ratio (5): 21 × 5 = 105 male students.

  For females you would multiply 21 by 4 = 84 female students.

  Add 105 + 84 to verify = 189.

• Question 167:

  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
  D. Phyletic gradualism

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  Phyletic gradualism is the view that evolution occurs at a more or less constant rate. Contrary to this view, punctuated equilibrium holds that evolutionary history consists of long periods of stasis punctuated by geologically short periods of evolution. This theory predicts that there will be few fossils revealing intermediate stages of evolution, whereas phyletic gradualism views the lack of intermediate-stage fossils as a deficit in the fossil record that will resolve when enough specimens are collected.

• Question 168:

  When a population reaches its carrying capacity?

  A. The population size begins to decrease.
  B. The population growth rate approaches zero.
  C. Other populations will be forced out of the habitat.
  D. Density-independent factors no longer play a role.
  E. Density-dependent factors no longer play a role.
  B. The population growth rate approaches zero.

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  Within a habitat, there is a maximum number of individuals that can continue to thrive, known as the habitat's carrying capacity. When the population size approaches this number, population growth will stop.

• Question 169:

  A helicopter shines its light into the ocean at an incidence angle of 30°. What is the angle of reflection? Assume index of refraction is n = 1.33 for water and n = 1 for air.

  A. 0°
  B. 15°
  C. 30°
  D. 60°
  E. Cannot be determined.
  C. 30°

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  This is a conceptual question that provides additional information to throw you off. Angle of incidence = Angle of reflection.

• Question 170:

  The density of helium is much lower than that of air. How does the speed of sound traveling through helium has compare to the speed of sound in air?

  A. It is faster.
  B. It is slower.
  C. It is the same speed.
  D. It cannot be determined without knowing their atomic masses.
  A. It is faster.

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  Sound travels much faster through helium than through air. Generally, the speed of sound can be calculated by speed = (k ?P / ), where k is the index of specific heats, P is pressure and is density. Since helium has a much lower density, it would have a higher speed.