1. Natural Selection Cartoons
Which inference (A, B, C or D) is correct for each cartoon?

3. Answer - D
With no limiting factors, any population will produce offspring in large numbers.  Some species may take longer than others (elephants vs. flies), but they can do so over time.

5. Answer - B
Any species has the potential to reproduce exponentially.  Organisms produce far more offspring than are needed to replace themselves.

7. Answer - D
Bacterial populations can develop resistance to antibiotics if almost all of the bacteria are killed by the antibiotic, but a few survivors, or even one, have random genetic mutations that protect them from the action of the drug.  Those survivors reproduce, resulting in entire populations that are not killed by that particular antibiotic.  In contrast to popular thought, humans do not become immune or resistant to antibiotics.

9. Answer - A
Adaptation is a change in allele frequency in a population over time in response to environmental pressures.  Individual organisms can’t change their genes so they do not adapt.  Biologists use the term “acclimatization” to refer to physiological (not genetic) changes that CAN take place in an individual, such as producing more red blood cells at higher altitude.  Acclimatization is NOT adaptation.

11. Answer - D
All of the answers reflect changes that can lead to speciation when interbreeding is prevented over a long period of time.

13. Answer - B
In biology, it is all about reproduction!  Organisms that leave the most offspring are considered to have the greatest fitness in the population.