A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example ofa. exaptation.b. changes in Hox gene expression.c. paedomorphosis.d. adaptive radiation.

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

Some biologists summarize evolution by natural selection with the phrase 'mutation proposes, selection disposes.' Mutation is a process that creates heritable variation. Explain what the phrase means.

Although cellulose and starch are identical in terms of stored chemical energy, our ability to harvest the energy from these two polysaccharides differs considerably. What is responsible for this difference?

Marsupial mammals give birth to young that complete their development in a pouch on the mother's abdomen. All the native mammals of Australia are marsupials, while these types of mammals are absent or uncommon on other continents. This observation is an example of a.developmental evidence for evolution;b. biogeogra­phic evidence for evolution;c. genetic evidence for evolution;d. fossil evidence for evolution;e. not useful evidence for evolution

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. Evidence indicates that early fish gulped air into primitive lungs, helping them survive in stagnant waters. The evolution of the swim bladder from lungs of an ancestral fish is an example ofa. an evolutionary trend.b. paedomorphosis.c. the gradual refinement of a structure with the same function.d. exaptation.

Why don't the biggest and strongest individuals in a population always produce the most offspring?a. The biggest and strongest individuals always have higher fitness.b. In some environments, being big and strong lowers fitness.c. Sometimes the biggest and strongest individuals may choose to have fewer offspring.d. Sometimes the number of offspring is not related to fitness.

If you were given a solution that has a pH of 8.5, what would be its concentration of protons? What is the difference in proton concentration between this solution and one that has a pH of 7?

Contrast the structure of glycogen and chitin in terms of their monosaccharides, glycosidic linkages, and interactions between polysaccharide chains.