Article: Predators may increase the biodiversity of communities by preventing a single species from becoming dominant. Such predators are known as keystone species and may have a profound influence on the balance of organisms in a particular ecosystem. Introduction or removal of this predator, or changes in its population density, can have drastic cascading effects on the equilibrium of many other populations in the ecosystem. For example, grazers of a grassland may prevent a single dominant species from taking over.

Question: What changes to a keystone predator can seriously affect an ecosystem's equilibrium?
Ans: Introduction or removal of this predator, or changes in its population density

Article: Rainfall along the coast averages about 10 inches (250 mm) of precipitation annually. The average (mean) rainfall is 10.65 inches (271 mm) and the median is 9.6 inches (240 mm). Most of the rainfall occurs during the cooler months. The months of December through March supply most of the rain, with February the only month averaging 2 inches (51 mm) or more of rain. The months of May through September tend to be almost completely dry. Though there are few wet days per month during the rainy period, rainfall can be heavy when it does fall. Rainfall is usually greater in the higher elevations of San Diego; some of the higher elevation areas of San Diego can receive 1115 inches (280380 mm) of rain a year. Variability of rainfall can be extreme: in the wettest years of 1883/1884 and 1940/1941 more than 24 inches (610 mm) fell in the city, whilst in the driest years as little as 3.2 inches (80 mm) has fallen for a full year. The wettest month on record has been December 1921 with 9.21 inches (234 mm).

Question: What is the average rainfall in February along the coast?
Ans: 2 inches (51 mm)

Article: In 1967, a new U.S. Department of Transportation (DOT) combined major federal responsibilities for air and surface transport. The Federal Aviation Agency's name changed to the Federal Aviation Administration as it became one of several agencies (e.g., Federal Highway Administration, Federal Railroad Administration, the Coast Guard, and the Saint Lawrence Seaway Commission) within DOT (albeit the largest). The FAA administrator would no longer report directly to the president but would instead report to the Secretary of Transportation. New programs and budget requests would have to be approved by DOT, which would then include these requests in the overall budget and submit it to the president.

Question: Who is the final person to approve the budget that is submitted?
Ans: president

Article: Duplications play a major role in shaping the genome. Duplication may range from extension of short tandem repeats, to duplication of a cluster of genes, and all the way to duplication of entire chromosomes or even entire genomes. Such duplications are probably fundamental to the creation of genetic novelty.

Question: What type of generation of genetic material has a big part in making the genome what it is?
Ans:
Duplications