21. Evolution

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

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. 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.

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.

Consider the reaction between carbon dioxide and water to form carbonic acid:CO2(g)+H2O(l)⇌CH2O3(aq)In the ocean, carbonic acid immediately dissociates to form a proton and bicarbonate ion, as follows:CH2O3(aq)+H+(aq)⇌CHO3−(aq)If an underwater volcano bubbled additional CO2 into the ocean, would this sequence of reactions be driven to the left or the right? How would this affect the pH of the ocean?

Since the modern synthesis, the technical definition of evolution is a change in in a over the course of generations.a. traits, species;b, allele frequency, population;c. natural selection, natural environment;d. adaptations, single organism;e. fitness, population

Even though marsupial mammals give birth to live young, an eggshell forms briefly early in their development. This is evidence that a.marsupials share a common ancestor with some egg-laying species;b. marsupials are not really mammals;c. all animals arose from a common ancestor;d. marsupial mammals were separately created by God;e. the fossil record of marsupial mammals is incorrect

Lysozyme, an enzyme found in human saliva, tears, and other secretions, catalyzes the hydrolysis of the ββ-1,4-glycosidic linkages in peptidoglycan. Predict the effect of this enzyme on bacteria and how it may be involved in human health.

Within a few weeks of treatment with the drug 3TC, a patient's HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?a. HIV can change its surface proteins and resist vaccines.b. The patient must have become reinfected with a resistant virus.c. A few drug-resistant viruses were present at the start of treatment, and natural selection increased their frequency.d. HIV began making drug-resistant versions of its enzymes in response to the drug.