MCAT Biology Question — Natural Selection
- Sep 16, 2014
- MCAT Question of the Day
A) Most mutations that occur in a species that is well-adapted to its niche are likely to be harmful.
B) Those individuals within a species that reproduce in the greatest numbers are fittest.
C) Genetic drift has no impact on the overall gene distribution in a population.
D) Ecosystems across all niches can only support a finite population of each organism.
One of the basic assumptions of natural selection is that organisms produce more offspring than the environment is capable of supporting. Then, some of those individuals survive to reproduce and others don’t – which survive are controlled by natural selection through environmental forces. That best matches choice (D).
A) False. Most mutations are silent or neutral as they occur in “junk DNA” or non-coding regions of the genome.
B) Tempting, but not technically true. Fitness is determined by the number of fertile offspring that survive to reproduce, not simply the total number of offspring.
C) Genetic drift is a form of random change in the gene distribution.
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