Midterm Exam #3

Which of the following statements is consistent with the principle of competitive exclusion?

A) Bird species generally do not compete for nesting sites. B) The random distribution of one competing species will have a positive impact on the population growth of the other competing species. C) Two species with the same fundamental niche will exclude other competing species. D) Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species. E) Natural selection tends to increase competition between related species. D

Which of the following accurately describes the ways in which climate change influences extinction risk?

A) Climate change causes extinction risk to increase randomly across the tree of life. B) Certain branches of the tree of life face greater extinction risks with climate change than other branches of the tree of life. C) As the climate changes, extinction risk increases at higher latitudes. D) There is no evidence that climate change influences extinction risks. C

Why do moderate levels of disturbance result in an increase in community diversity?

A) Habitats are opened up for less competitive species. B) Competitively dominant species infrequently exclude less competitive species after a moderate disturbance. C) The environmental conditions become optimal. D) The resulting uniform habitat supports stability, which in turn supports diversity. E) Less-competitive species evolve strategies to compete with dominant species. A

With which of the following statements would a biologist be most inclined to agree?

A) Humans and apes represent divergent lines of evolution from a common ancestor. B) Humans evolved from New World monkeys. C) Humans have stopped evolving and now represent the pinnacle of evolution. D) Humans evolved from chimpanzees. E) Humans and apes are the result of disruptive selection in a species of gorilla. A

A female cat in heat urinates more often and in many places than female cats who are not in heat. Male cats are attracted to the urine deposits. Which of the following is a proximate cause of this increased urination?

A) It announces to the males that she is in heat. B) Female cats that did this in the past attracted more males. C) It is a result of hormonal changes associated with her reproductive cycle. D) The female cat learned the behavior from observing other cats. E) All of the above are ultimate causes of behavior. C

Imagine that a deep temperate-zone lake did not turn over during the spring and fall seasons. Based on the physical and biological properties of limnetic ecosystems, what would be the difference from normal seasonal turnover?

A) Lakes would suffer a nutrient depletion in surface layers. B) The lake would be uniformly cold during the winter and summer. C) The lake would fail to freeze over in winter. D) An algal bloom of algae would result every spring. A

With regard to understanding the evolution of cooperation, the principal prediction that can be made from the expression Br > C is that ________.

A) natural selection will favor cooperation among close relatives B) cooperation evolves because it benefits all members of a species C) cooperation evolves because it enhances the species' fitness D) selection favors self-sacrifice in reproduction E) natural selection will favor cooperation among any individuals A

In biology, an arms race is most likely to occur when ________.

A) predators become dominant over their prey species leading to the local extinction of the prey B) a new species evolves into two separate species C) a new niche is created because of interactions between species D) there is a repeating cycle of reciprocal adaptation (co-evolution) E) a prey species adapts and is able to coexist with its predators D

Which of the following most often controls the rate of nutrient cycling in ecosystems?

A) the rate of decomposition of detritus B) primary production C) secondary productivity D) both primary and secondary productivity A

The main reason that polar regions are cooler than the equator is that ________.

A) there is more ice at the poles. B) sunlight strikes the poles at an lower angle. C) the poles are farther from the sun. D) the poles have a thicker atmosphere. E) the poles are permanently tilted away from the sun. B

Use BiomeViewer (http://www.hhmi.org/biointeractive/biomeviewer) to answer this question: Which biome occupies a fairly consistent band in the Northern hemisphere between the Tundra and other more southern biomes?

Boreal Forest

According to the definition of Keystone Species in your textbook, which of the following best describes a keystone species?

carnivorous animal eats

__________ refers to the type of interaction where one organism makes the environment more suitable for another organism. In contrast, ______________ refers to the type of interaction where one organism makes the environment less suitable for another organism.

commensalism amensalism

Refer to Figure 53.8 in your text book (also shown in class on the slide titled "Net Primary Productivity (NPP) Varies Among Biomes"). Which ecosystem type represented in the figure contributes least to global primary productivity?

coral reefs and algal beds

Which of the following are measurements of Alpha Diversity? Select all that apply

no - dispersion of a population yes- density of individuals no - evenness no - overlap in species between locations yes - species richness no - phylogenetic

Fill in the blanks with the names of biodiversity metrics discussed in class. Two communities with the same number of species have equal ________________. A species that has far more individuals than any other species in the community has high _________________. A sample that contains similar numbers of individuals from different species has high _________________. Diversity is a measure of how similar two different communities or samples are ______________.

relative abundance species abundance phylogenetic diversity Beta

Which statements about K are correct? Select all of the correct answers.

yes - K varies in space. yes - K varies in time. no - K is constant for any given species. no - K varies among populations.

Use BiomeViewer (http://www.hhmi.org/biointeractive/biomeviewer) to answer this question: The biome of Jilin, China (44.5° N, 127.7° E) is classified as temperate deciduous forest. Aproximately 800 miles to the west, but at the same latitude, the biome of Saikhandulaan, Mongolia (44.5° N, 109.3° E) is classified as desert. What is the best explanation of the differences between the biomes of these two locations?

The Mangolia desert gets less rainfall

Use BiomeViewer (http://www.hhmi.org/biointeractive/biomeviewer) to answer this question: What is the most common biome along the equator?

Tropical Rain Forest

Why would you expect some white-fronted bee-eaters to fly very far away from their nests to forage when there are food sources nearby? Base your answer on your knowledge of cost—benefit analyses.

A) More pathogens tend to immigrate into newer habitats. B) Intermediate host species are more motile and transport pathogens to new areas. C) Pathogens evolve more efficient forms of reproduction in new environments. D) Hosts in new environments have not had a chance to become resistant to the pathogen through natural selection. E) New environments are almost always smaller in area so that transmission of pathogens is easily accomplished between hosts.

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be TRUE?

A) Polar bears can provide more food for humans than seals can. B) The total biomass of the fish is lower than that of the seals. C) Seal meat probably contains the highest concentrations of fat-soluble toxins. D) Seal populations are larger than fish populations. E) The fish can potentially provide more food for humans than the seal meat can. E

Which of the following is required for a behavioral trait to evolve by natural selection?

A) The behavior is determined entirely by genes. B) The behavior is the same in all individuals in the population. C) An individual's reproductive success depends in part on how the behavior is performed. D) The behavior is not genetically inherited. C

As N approaches K for a certain population, which of the following is predicted by the logistic equation?

A) The growth rate will not change. B) The growth rate will approach zero. C) The population will show an Allee effect. D) The population will increase exponentially. E) The carrying capacity of the environment will increase. B

How does inefficient transfer of energy among trophic levels result in the typically high endangerment status of many top-level predators?

A) Top-level predators are destined to have small populations that are sparsely distributed. B) Predators have relatively large population sizes. C) Predators are more disease-prone than animals at lower trophic levels. D) Predators have short life spans and short reproductive periods. E) Top-level predators are more likely to be stricken with parasites. A

Adult tunicates (urochordates) lack notochords, however, larval urochordates have them and use them to ________.

A) aid in swimming; adults are sessile and thus no longer propel themselves. B) stiffen their bodies; in adults, the notochord is replaced by a column of bone. C) induce tissue differentiation; in adults, tissue is already differentiated. D) organize their nervous systems; adults' nervous systems are fully developed and do not A

Which marine zone would have the lowest rates of primary productivity (photosynthesis)?

A) aphotic B) pelagic C) neritic D) continental shelf E) intertidal A

Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that ________.

A) arthropods evolved before vertebrates did. B) extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates. C) ancestral arthropods must have been poorly adapted to aquatic life, thus experienced a selective pressure to invade land. D) vertebrates evolved from arthropods. E) arthropods have had more time to co-evolve with land plants than have vertebrates. E

In house sparrows (Passer domesticus) it is generally found that both males and females care for the eggs and young. However, some male house sparrows do not provide parental care. In addition, it is known that young that receive parental care from both the male and female are more likely to survive to fledging (leaving the nest). Which of the following activities by males that do NOT provide parental care would represent the most beneficial trade-off for the reduced survival of their offspring?

A) attacking the nests of neighboring males B) mating with additional females and fathering more eggs C) eating to build up energy stores for migration D) grooming to eliminate parasites from their feathers B

As you study two closely related predatory insect species, Species A and Species B, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap, Species A hunts at night and Species B hunts in the morning. When you bring them into the laboratory and isolate the two different species, you discover that the offspring of both species are found to be nocturnal. You have discovered an example of ________.

A) character displacement B) mutualism C) Batesian mimicry D) resource partitioning A

A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, system of tubes for gas exchange, and modified segmentation. A knowledgeable zoologist should predict that the adults of this species would also feature ________.

A) eight legs B) an open circulatory system C) two pairs of antennae D) a sessile lifestyle B

Suppose you traveled back in time and located the first animals to have evolved feathers. You found that these animals were tree-dwelling ectotherms, able to run quickly but unable to fly. You also noticed that only males had feathers. Which hypothesis of feather evolution would these data most support? Feathers initially evolved in a role associated with ________.

A) flight B) insulation C) sexual selection D) gliding C

What factor could potentially increase the length of a food chain?

A) increased extinction rates of species in the food chain B) multiple species of herbivores feeding on each plant species C) having a single species of herbivore feeding on each plant species D) decrease in the amount of energy lost in a tropic level as it passes to the next level B

Which of the following energy sources used in the U.S. is considered renewable, is intermittent in its availability, and can have deadly or catastrophic accidents.

A) natural gas B) hydropower C) nuclear D) biofuel B

Why is energy lost when herbivores eat primary producers?

Primary producers have energy stored in indigestible substances.

Which of the following statements about a keystone species is most likely to be true?

Removing a keystone species will result in drastic change in ecosystem