Adaptive radiations can be a direct consequence of three of the following four factors. Select the exception:
a. Vacant ecological niches
b. Genetic drift
c. Colonization of an isolated region that contains suitable habitat and few competitor species
d. Evolutionary innovation

Which of the following best characterizes an adaptive radiation?

a. Descendant species occupy a large geographic area.

b. A single lineage diversifies rapidly, and descendant species occupy many habitats and ecological roles.

c. Natural selection is particularly intense, because disruptive selection occurs.

d. Species recover after a mass extinction.

What two conditions must be present for osmosis to occur? Integral membrane proteins are anchored in lipid bilayers.

How does the hydrolysis of ATP result in the movement of a motor protein along a cytoskeletal filament?

Ancient photosynthetic prokaryotes were very important in the history of life because they

a. Produced the oxygen in the atmosphere.

b. Are the oldest-known archaea.

c. Were the first multicellular organisms.

d. Showed that life could evolve around deep-sea vents.

Which of the following groups of amino acid residues would likely be found in the portion that crosses the lipid bilayer?

a. Acidic

b. Basic

c. Polar uncharged

d. Nonpolar

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

a. Synthesis of small RNA polymers by ribozymes

b. Formation of molecular aggregates with selectively permeable membranes

c. Formation of protocells that use DNA to direct the polymerization of amino acids

d. Abiotic synthesis of organic molecules