21. Evolution

Which of the following is an observation or inference on which natural selection is based? (A) Individuals do not vary in their heritable characteristics. (B) Only well-adapted individuals produce offspring. (C) Species produce more offspring than the environment can support. (D) Nearly all of each individual's offspring will survive and reproduce.

Which of the following is not an observation or inference on which natural selection is based?

a. There is heritable variation among individuals.

b. Poorly adapted individuals never produce offspring.

c. Species produce more offspring than the environment can support.

d. Only a fraction of an individual's offspring may survive.

True or false? Some traits are considered vestigial because they existed long ago.

What types of drugs have helped reduce the death rate due to tuberculosis infection, and why have they become less effective more recently?

What are three ways monosaccharides differ from one another?

Complete this concept map describing potential causes of evolutionary change within populations.

Which of the following observations is not part of the theory of natural selection?

a. Populations of organisms have more offspring than will survive

b. There is variation among individuals in a population

c. Modern organisms are unrelated

d. Traits can be passed on from parent to offspring

e. Some variants in a population have a higher probability of survival and reproduction than other variants do

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by MRSA. How can this best be explained?

a. A patient must have become infected with MRSA from another community.

b. In response to the drug, S. aureus began making drug- resistant versions of the protein targeted by the drug.

c. Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

d. S. aureus evolved to resist vaccines.