21. Evolution

Traits that are derived from a common ancestor, like the bones of human arms and bird wings, are said to be .

What holds cellulose molecules together in bundles large enough to form fibers?a. the cell wallb. peptide bondsc. hydrogen bondsd. hydrophobic interactions

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?a. Forelimb evolution was adaptive in people and bats, but not in whales.b. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.c. Genes mutate faster in whales than in humans or bats.d. Whales are not properly classified as mammals.

Natural selection is sometimes described as 'survival of the fittest.' Which of the following best measures an organism's fitness?a. how many fertile offspring it producesb. how strong it is when pitted against others of its speciesc. its ability to withstand environmental extremesd. how much food it is able to make or obtain

How can evolutionary fitness be measured? Select True or False for each statement.T/F Document how long individuals survive.T/F Count the number of healthy, fertile offspring produced.T/F Determine which individuals are strongest.T/F Determine which phenotype is the most common.

What are the primary functions of carbohydrates in cells?a. cell identity, energy storage, raw material source for synthesis, and structureb. catalysis, energy storage, metabolism, and structurec. catalysis, digestion, energy storage, and information storaged. energy storage, information storage, polymerization, and raw material source for synthesis

Which of the differences listed here could be found among molecules of the same monosaccharide? Select True or False for each statement.T/F There is a difference in the orientation of a hydroxyl group in the ring form.T/F There is a difference in the number of carbons.T/F There is a difference in the position of the carbonyl group in the linear form.T/F There is a difference in the overall shape of the molecule—one is a ring and the other is linear.

The best definition of evolutionary fitness is .a. physical health;b. the ability to attract members of the opposite sex;c. the ability to adapt to the environment;d. survival and reproduction relative to other members of the populatione. overall strength

The theory of common descent states that all modern organisms .a. can change in response to environmental change;b. descended from a single common ancestor;c. descended from one of many ancestors that originally arose on Earth;d. have not evolved;e. can be arranged in a hierarchy from 'least evolved' to 'most evolved'

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is thata. humans and chimpanzees share a relatively recent common ancestor.b. humans evolved from chimpanzees.c. chimpanzees evolved from humans.d. convergent evolution led to the DNA similarities.

According to data presented in this chapter, which of the following are correct? Select True or False for each statement.T/F When individuals change in response to challenges from the environment, their altered traits are passed on to offspring.T/F Species are created independently of each other and do not change over time.T/F Populations—not individuals—change when natural selection occurs.T/F The traits of populations become more perfect over time.

Explain the logic behind the claim that the nuclear envelope is a synapomorphy that defines eukaryotes as a monophyletic group.

Explain the logic behind the claim that the nuclear envelope is a synapomorphy that defines eukaryotes as a monophyletic group.

An adaptation is a trait of an organism that increases .a. its fitness;b. its ability to survive and replicate;c. in frequency in a population over many generations;d. A and B are correct;e. A, B, and C are correct

The DNA sequence for the same gene found in several species of mammals .a. is identical among all species;b. is equally different between all pairs of mammal species;c. is more similar between closely related species than between distantly related species;d. provides evidence for the hypothesis of common descent;e. more than one of the above is correct