Biology ch. 54: Community Ecology – Flashcards

Under which of the following circumstances would interspecific competition be most obvious? A. when resources are most abundant B. in the presence of a keystone species C. when organisms have quite different ecological niches D. among species whose trophic levels are different E. when a non-native organism is introduced to a community

The niche of an animal is _____.

When goats were introduced to an island off the California coast, the goats inhabited the same areas and ate the same plants as the native deer. The deer population dwindled and finally disappeared. This is an example of _____.

Flounder is a type of fish that looks like the seafloor. This is an example of _____.

The flower fly resembles a honeybee, but the flower fly has no stinger. This is an example of _____.

The poison-arrow frogs Dendrobates of tropical America are all brightly colored and have very similar patterns. Although each species is distasteful to predators and all possess toxic skin secretions, some of the species live quite separate from the others. The adaptive relationship among these species is best termed _____.

A leech that attaches itself to a swimmer is an example of _____.

Certain species of acacia trees in Central and South America have hollow thorns that house stinging ants, which attack anything that touches the tree. The ants feed on nutrients produced by the acacias. This is an example of _____.

Which example below correctly lists members of a desert ecosystem from the producer level to the top consumer level? A. detritivores, brittlebush, collared lizard, red-tailed hawk B. red-tailed hawk, collared lizard, pallid-winged grasshopper, brittlebush C. pallid-winged grasshopper, collared lizard, red-tailed hawk, detritivores D. brittlebush, pallid-winged grasshopper, collared lizard, red-tailed hawk E. none of the above

A field contains 950 kg of plant material. How many kilograms of tertiary consumers could be supported?

What is the key difference between a dominant species and a keystone species? A. There is no difference. The two terms are synonymous. B. Dominant species alter the structure or dynamics of the environment; keystone species are the most abundant. C. Dominant species are the most abundant; keystone species exert control through important roles or niches. D. The removal of a dominant species from a community has more impact than removing a keystone species. E. Keystone species are more successful at evading their predators and the impacts of disease.

In the North Pacific, sea otters are keystone predators. A reduction in their numbers has resulted in what changes in the marine community? A. competitive exclusion inevitably reduced species richness B. mutualism among prey species maintained species diversity C. the orcas have begun to prey on sea urchins D. the absence of a keystone species decreased community diversity E. resource partitioning allowed otherwise competing species to coexist

A species of malaria-carrying mosquito lives in a forest in which two species of monkeys, A and B, coexist. Species A is immune to malaria, but species B is not. The malaria-carrying mosquito is the chief food for a particular kind of bird in the forest. If all these birds were suddenly eliminated by hunters, which of the following would be an immediately observable consequence? A. increased mortality (death rate) in monkey species A B. increased mortality in monkey species B C. increased mortality in the malaria-carrying mosquitoes D. emergence of malaria-resistant strains in monkey species B E. emergence of malaria-sensitive strains in monkey species A

A lake community with four trophic levels suddenly suffers from algal blooms. Using the strategy of biomanipulation, an ecologist may propose _____. A. removing zooplankton B. adding mineral nutrients to the water C. adding fish that eat zooplankton D. removing fish that eat zooplankton E. removing the fourth trophic level in the lake

The current view of biological communities is _____.

Succession of communities occurs because _____.

Which statement below correctly describes conditions on a glacier moraine during the reign of pioneer species? A. Vegetation consists of sphagnum bogs on poorly drained flat areas. B. Decomposition of acidic spruce needles reduces the pH of the soil. C. Low nitrogen content causes many plants to have yellow leaves. D. Alder forms dense thickets up to 9-meters-tall. E. Bare soil is acidic due to the carbonate compounds in the parent rocks

_____ views a community as the chance assemblage of organisms with similar abiotic needs.

What are two key factors in species richness equatorial-polar gradients?

When equilibrium is reached on an island, _____.

What happens to the number of species in a community as the area of that community increases?

The potential evapotranspiration is determined by ______.

Which of the following is the definition of a pathogen? A. a group of populations living in close enough proximity to interact regularly B. a disease-causing microorganism C. a species that kills and eats another species D. a species that is killed and eaten by another E. a type of interspecific interaction that benefits both species

What is a zoonotic pathogen?