Alex is a student with Strep throat (caused by a strain of b…

Alex is a student with Strep throat (caused by a strain of bacterium) who is given a prescription for an antibiotic and is told to take the drug for two weeks. After a week, he feels better and stops taking the drug. Two months later, Alex again shows symptoms of Strep throat and decides to finish the leftover antibiotic rather than going to the doctor again. Two months after that, he develops Strep throat for a third time and returns to the doctor. This time, the antibiotic does not work. The doctor runs a test and discovers that the bacterial strain Alex is carrying is antibiotic resistant. What most likely happened?

The color of a certain species of beetle is determined by a…

The color of a certain species of beetle is determined by a single gene. Two beetles homozygous for green coloration (meaning they have two copies of the green allele) produce a single offspring with brown coloration. Brown color must have appeared in this offspring as a result of

Because natural populations tend to produce more individuals…

Because natural populations tend to produce more individuals than can be supported by the environment, individuals must compete for resources.  Some individuals are better competitors than others, meaning that not all individuals will survive.  In turn, some individuals will have higher fitness than others. This describes: