Draw a small concept map showing how selection, genetic drift, gene flow, and mutation relate to genetic variation.

Explain why continuous growth enhances the phenomenon known as phenotypic plasticity.

The heritable differences among organisms are a result of .a. differences in their DNA;b. mutation;c. differences in alleles;d. A and B are correct;e. A, B, and C are correct

According to the RNA world model, a ribozyme would replicate by creating a double-stranded RNA intermediate. Would you expect the intermediate to have the same catalytic activity as the original ribozyme? Justify your answer with an explanation.

A new plant species C, which formed from hybridization of species A(2n = 16) with species B(2n = 12), would probably produce gametes with a chromosome number ofa. 12.b. 14.c. 16.d. 28.

The risks faced by small populations include .a. erosion of genetic variability through genetic drift;b. decreased fitness of individuals as a result of inbreeding;c. increased risk of experiencing natural disasters;d. A and B are correct;e. A, B, and C are correct

Ivory from elephant tusks is a valuable commodity on the world market. As a result, male African elephants with large tusks have been heavily hunted for the past few centuries. Today, male elephants have significantly shorter tusks at full adulthood than male elephants in the early 1900s. This is an example of .a. diversifying selection;b. stabilizing selection;c. directional selection;d. chance;e. more than one of the above is correct

A horse (2n = 64) and a donkey (2n = 62) can mate and produce a mule. How many chromosomes would there be in a mule's body cells?a. 31b. 62c. 63d. 126

Antibiotic resistance is becoming common among organisms that cause a variety of human diseases. All of the following strategies help reduce the risk of antibiotic resistance evolving in a susceptible bacterial population except .a. using antibiotics only when appropriate, for bacterial infections that are not clearing up naturally;b. using the drugs as directed, taking all the antibiotic over the course of days prescribed;c. using more than one antibiotic at a time for difficult-to-treat organisms;d. preventing natural selection by reducing the amount of evolution the organisms can perform;e. reducing the use of antibiotics in non–health-care settings, such as agriculture