Chapter 15

Which answer below is an example of mutualism?

Protists in the gut of a termite help it digest cellulose E coli in the human intestine help us absorb vitaminK

Why is it hotter at the equator than at the Poles?

The angle at which sunlight hits the earth leads to a given amount of solar energy being spread over a smaller area at the equator than at the Poles.

The 10% rule of energy-conversion efficiency:

1. explains why big, fierce animals are so rare. 2. explains why the biomass of herbivores must exceed that of carnivores. 3. limits the length of food chains. 4. suggests that 90% of what an organisms eats is used in cellular respiration or is lost as feces. 5. All of the above are correct.

The gazelle can change direction very quickly while being chased by a cheetah (fastest land animal). The gazelle uses which method of defense listed below?

Behavioral Defense

Chemical defenses are more common among plants than animals because:

Chemical defenses are more common among plants than animals because: 1. plants cannot move to escape predators and so must develop other deterrents. 2. the cell wall can contain the chemicals more effectively than a simple plasma membrane. 3. mechanical defenses against predators can evolve only in animals. 4. parasite loads in plants are significantly higher than in animals. 5. All of the above are correct.

Which of the following statements about an organism's niche is incorrect?

It may be occupied by two species, as long as they are not competitors.

The three case studies in the preceding slides illustrate how parasites get around what difficulty?

Moving between the hosts

An ecosystem consists of ______ in a given area.

all the living organisms and non-living materials

When moist wind from an ocean blows onshore toward a mountain range:

as the air rises, it pulls moisture from the ground, causing the higher elevations to be drier. as the air goes over the top of the mountain and falls back down toward lower elevations, it holds less moisture, creating a "rain shadow" zone of unusually high precipitation. as the air rises, it holds less moisture, causing the dissipation of all clouds as the moist air goes over the top of the mountain and falls back down toward lower elevations, it holds even more moisture, creating a "rain shadow" desert with very little precipitation. 5. None of the above are correct.

The "ghost of competition past" refers to the fact that:

competition often leads to character displacement, which remains even after direct competition is reduced.

"Top" carnivores:

consume primarily carnivores.

Rabid animals:

froth at the mouth so as to increase the likelihood that the rabies-causing virus is passed on to another host.

In a commensal relationship:

one species benefits while the other neither benefits nor is harmed.

What might the competitive exclusion principle cause when 2 similar species occur together

one species will become locally extinct character displacement will occur - both

Nitrogen enters the food chain:

primarily through soil-dwelling bacteria that "fix" nitrogen by attaching it to other atoms.