Bio 182 Exam 4 Practice test

What factors promote the recent spread of drug-resistant pathogens?

Aggressive use of antibiotics has provided strong selective pressure favoring mutants able to tolerate drugs.

Imagine that a time traveler was able to successfully travel 2 billion years back in time and modified the environment so that photosynthesis and respiration were completely coupled (i.e., there was no "leakage" of products from respiration or photosynthesis). How would this affect Earth's present-day atmosphere, if at all?

Atmospheric O2 levels would decrease.

Why do we think that male Neanderthals mated with non-African ancestral Homo sapiens?

Because Neanderthal nuclear DNA sequences are present in the human gene pool, and Neanderthal mtDNA sequences are not.

Which of the following statements is TRUE regarding CO2?

CO2 is a greenhouse gas. CO2 plays a vital role in maintaining Earth's temperature. CO2 is released as a product of respiration. CO2 can be produced by natural and man-made processes.

Why has this trend continued in the last 50 years?

Combustion of Fossil Fuels

In reviewing historical records and ice core data, researchers noted that atmospheric CO2 levels started to rise as humans began to burn fossil fuels. This is an example of what type of relationship?

Correlation

Primary producers fix phosphorus into biologically useful molecules just like they fix carbon and, in some cases, nitrogen.

False

The CO2 level is _____ during winter in the northern hemisphere compared to levels in the summer.

Higher

Primary producers are present in every biome, including the deep sea. How can there be primary producers in the deep sea when sunlight does not penetrate to these depths?

Primary producers in the deep sea use energy from chemical reactions to drive the reduction of CO₂ to organic compounds.

Current predictions of global climate change indicate that temperatures may rise by as much as 5°C in some areas. Imagine a chaparral location that experiences 100 cm of average annual rainfall and an average annual temperature of 15°C. If there were an increase of 5°C, what would you expect?

The Region would become Savannah

Researchers use the denaturation temperatures of hybrid double helices to compare evolutionary relatedness. Complementary strands denature at 95 degrees. A researcher engineers a hybrid strand from two species and it denatures at 93 degrees. What does this mean?

The hybrid double helices are less complementary than the non-hybrid.

Figure 49.7 shows observed temperature changes versus those predicted for natural causes of increased temperature and natural plus anthropogenic causes of increased temperature. How would the lines be different if humans were predicted to have no impact on global temperatures?

The line for natural causes would be the same as that for anthropogenic plus natural causes.

If the Earth spun on an axis that was perfectly perpendicular to the equator, how might this affect latitudinal differences in incoming solar radiation?

There would still be latitudinal differences because incoming solar radiation would be spread across a greater area at the poles than at the equator.

Deserts caused by a rain shadow occur on the east (leeward) side of the Sierra Nevada range in California. Why does the desert exist on the east side, but not the west side of the range?

Warm, moist air coming off the ocean rises as it encounters the mountain range and releases all its water as it moves up the mountain and the air cools. Dry air moving down the other side of the mountain causes arid desert.

Carbon dioxide combines with water to form a weak _____; this has caused the pH of seawater to go _____.

acid; down

As oceans acidify, carbonate ions in the ocean:

become less abundant and less available to organisms that build calcium carbonate skeletons.

Glacial expansion correlates with _______ amounts of CO2 in the atmosphere and temperatures _______ than those measured in 1950.

decreasing; lower

Which of the following groups of biomes is listed in order of greatest to lowest potential evapotranspiration ratio?

desert, deciduous forest, rain forest

Which of the following groups is monophyletic?

humans plus chimpanzees and bonobos

Invasive species have particularly devastating effects on islands because:

island species have typically evolved with few competitors and predators.

Warm air is _____ dense than cold air, and warm air holds _____ moisture than cold air.

less; more

In either freshwater or marine biomes, which regions would you expect to have the HIGHEST productivity?

near the surface where sunlight penetrates

Leopards require large amounts of space in order to maintain viable population numbers. If conservation biologists establish reserves that are large enough to preserve populations of leopards, then:

other species, endangered or not, will also be protected in that same area.

Because CO2 is a greenhouse gas, a rise in CO2 levels correlates with a(n):

rise in temperature.

The common phrase "Humans evolved from chimpanzees" is inaccurate. In reality, the evolutionary relationship between chimpanzees and humans is:

that humans and chimpanzees share a relatively recent common ancestor.

Which of the following will help SLOW the rate of increase of atmospheric CO2?

turning off the light in an empty room driving more fuel-efficient cars using solar power instead of fossil fuels to help conserve natural resources