MCAT Biology Question — Infection
- Jan 22, 2017
- MCAT Question of the Day
An infectious agent is probably a virus instead of a bacterium if it:
A. lacks membrane-bound organelles
B. cannot reproduce in acellular culture
C. has a length of 1μm, about the size of a mitochondrion
D. contains DNA
Click for Explanation
Viruses possess DNA or RNA but not both, require a host cell’s reproductive machinery in order to reproduce, and have a size 10-100nm. For the MCAT: eukaryotic cell > bacterium (roughly size of mitochondrion) > virion (roughly size of protein, roughly 100x smaller than bacterium, 1000x smaller than eukaryotic cell, cannot be seen with optical microscope).
A. lacks membrane-bound organelles, incorrect, Both viruses and bacteria lack membrane-bound organelles.
B. cannot reproduce in acellular culture, correct. Viruses require host cells in order to reproduce.
C. has a length of 1μm, about the size of a mitochondrion, incorrect, This is the size of a bacterium.
D. contains DNA, incorrect, Both bacteria and viruses may contain DNA.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT expert using the form below. No obligation, just expert advice.
Search the Blog
Free ConsultationSchedule Now
MCAT Blog How to Review MCAT Full-Lengths
Free MCAT Practice AccountNeed great MCAT practice?
Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a half-length diagnostic exam and one of our full-length MCAT practice exams.Learn More