MCAT Prep Workshop Quiz

To separate two molecules that have large differences in boiling point, which of the following methods should be used?

• fractional distillation

• simple distillation

• steam distillation

• vacuum distillation

Which of the following separation techniques is based on the relative solubility of a pure substance as compared to an impure substance?

• crystallization

• fractional distillation

• extraction

• chromatography

Consider proteins eluting through a cation-exchange chromatography column. If the pH within the column is greater than the pI of the proteins, which of the following will occur?

• The proteins will be retained by the stationary phase.

• The proteins will be retained by the mobile phase.

• The pH will have no influence on the elution of the proteins.

• The proteins will not elute through the column.

The organic molecule (left) contains which of the following functional groups?

• Enamine

• Imine

• Amide

• Amine

Which of the following correctly describes a "threshold" as it relates to sensation?

I. The minimum intensity of a signal or stimulus necessary to be detected half of the time.

II. The minimum intensity of a signal or stimulus that can be detected.

III. The maximum amount of signal or stimulus that can elicit a response.

• I only

• II only

• I and II

• I, II, and III

Which of the following correctly describes Weber's Law?

• Sensation is limited by physical characteristics, such as the anatomy of the ear.

• A signal can either be detected ("hit"), not detected ("miss"), inaccurately detected ("false positive"), or accurately ignored ("accurate rejection").

• The threshold for detecting a change in a stimulus is proportional to its initial intensity.

• The threshold for detecting a change in a stimulus is constant across all forms of stimuli.

Humans have the ability to detect sounds at least 50% of the time once frequencies reach 20Hz. The total range of frequencies detectable is considered to be 20Hz - 20,000Hz. Here, 20Hz is an example of which of the following?

• difference threshold

• maximum threshold

• minimum threshold

• absolute threshold

Which type of sensory receptor is most significant for our sense of hearing?

• chemoreceptor

• mechanoreceptor

• baroreceptor

• nociceptor

Given a k value of 0.4, how heavy must a dumbbell be for a person to detect a change from the initial weight of 10kg?

• 4kg

• 10kg

• 14kg

• 25kg

In a particular area, two distinct populations of finches arise. One population has longer beaks and one population has shorter beaks. The population of finches with longer beaks eventually outcompetes the population with shorter beaks. Which of the following concepts does this illustrate?

• group selection

• kin selection

• artificial selection

• sexual selection