If you’re preparing for the Medical College Admission Test, you are going to want to consult the experts. These selections from Kaplan’s MCAT Question of the Day series can help you sharpen your skills as you prepare to begin your potential journey into medical training. Kaplan is a preferred provider through AMA Member Benefits PLUS.
The questions below come from three of the four MCAT sections—biological and biochemical foundations of living systems; chemical and physical foundations of biological systems; and psychological, social and biological foundations of behavior. A fourth section, critical analysis and reasoning skills (commonly referred to as CARS), is based largely on inference.
Medicine can be a career that is both challenging and highly rewarding but figuring out a medical school’s prerequisites and navigating the application process can be a challenge unto itself. For students preparing for the medical school, the AMA premed glossary guide has the answers to frequently asked questions.
Question: How does prokaryotic DNA differ from eukaryotic DNA?
I. Prokaryotic DNA lacks nucleosomes.
II. Eukaryotic DNA has telomeres.
III. Prokaryotic DNA is replicated by a different DNA polymerase.
IV. Eukaryotic DNA is circular when unbound by centromeres.
A. I only
B. IV only
C. II and III only
D. I, II, and III only
The correct answer is D.
Kaplan explains why: Prokaryotic DNA is circular and lacks histone proteins, and thus does not form nucleosomes. Both prokaryotic and eukaryotic DNA are replicated by DNA polymerases, although these polymerases differ in identity. Eukaryotic DNA is organized into chromatin, which can condense to form linear chromosomes; only prokaryotes have circular chromosomes. Only eukaryotic DNA has telomeres.
Question: Sodium hypochlorite (NaClO) is used as a disinfectant and has also been shown to treat chronic skin inflammation. What is the oxidation number of chlorine in NaClO?
The correct answer is C.
Kaplan explains why: In NaClO, sodium carries its typical +1 charge, and oxygen carries its typical -2 charge. This means that the chlorine atom must carry a +1 charge in order to balance the overall charge of zero.
Question: A medical student is feeling a high level of stress due to upcoming exams and pressure from his family to engage in activities at home. He chooses to go the gym for a workout to help himself relax. This workout is which type of stress?
The correct answer is D.
Kaplan explains why: A positive stressor creates eustress. Because working out is used to relax, it is considered a eustress. Hassle, choice (A), and frustration, choice (B), are both types of distress, choice (C), or negative stressors.