Ecology Chapter 8

The number of wild horses per square kilometer in a prairie is the horse populations a. density. b. dispersion. c. size. d. birth rate.

a. density.

A true statement about parasitism is that parasites a. may cause their hosts to become more vulnerable to predators. b. do not live on or in their hosts' bodies. c. are always animals and never plants. d. immediately kill their hosts.

a. may cause their hosts to become more vulnerable to predators.

Which of the following is one of the main properties used to describe a population? a. number of individuals b. color of individuals c. number of species d. kind of adaptations

a. number of individuals

The difference between a predator and a parasite is that a predator a. usually kills and eats its prey. b. benefits from another organism. c. lives in or on a host. d. harms another organism.

a. usually kills and eats its prey.

Which of the following would most likely cause a large number of density-independent deaths in a population? a. winter storms b. disease-carrying insects c. predators d. limited resources

a. winter storms

Which of the following statements is correct? a. An organism's niche is only the part of its habitat that it eats. b. An organism's habitat is a location. c. Habitat and niche are the same thing. d. An organism's niche is outside its habitat.

b. An organism's habitat is a location.

Which of the following statements explains why the growth of orchids on the high branches of tropical trees is an example of commensalism? a. The orchids draw nourishment from the trees. b. The trees are neither benefited nor harmed. c. The orchids keep parasites away. d. The trees receive nutrients from the orchids.

b. The trees are neither benefited nor harmed.

Each of the following is an example of a parasite except a. a roundworm in a human's intestine. b. a cow in a pasture. c. a tick on a cat. d. mistletoe on a tree.

b. a cow in a pasture.

An example of a population is a. all trees in a forest. b. all maple trees in a forest. c. all plants in a forest. d. all animals in a forest.

b. all maple trees in a forest.

The relationship between acacia trees and the ants that live on them is an example of a. commensalism. b. mutualism. c. parasitism. d. predation.

b. mutualism.

The relationship between a Canadian lynx and a snowshoe hare is an example of a. parasite and host. b. predator and prey. c. competition. d. mutualism.

b. predator and prey.

Which of the following is not an example of exponential growth? a. rabbit populations after being introduced to Australia b. reindeer of the Pribilof Islands after eating most of the lichens c. a bank account that earns interest d. mold appearing on bread overnight

b. reindeer of the Pribilof Islands after eating most of the lichens

Which of the following reproductive situations will limit a population's biotic potential? a. the minimum number of offspring each pair can produce b. the maximum number of offspring each individual can produce c. the number of interactions each individual has d. the size of offspring each individual can produce

b. the maximum number of offspring each individual can produce

A population's growth rate is its ______ rate minus its _____ rate.

birth, death

Which of the following statements is not correct? a. Mutualism is a type of symbiosis. b. Yucca moths and yucca plants have a symbiotic relationship. c. Symbiosis is a relationship in which two organisms live apart. d. Coyotes and foxes are competitors because they feed on the same kinds of animals.

c. Symbiosis is a relationship in which two organisms live apart.

A species of plant has exponential growth after it is introduced into an area where it has never lived. Which statement best describes exponential growth? a. Each individual plant grows much larger than usual. b. The population immediately decreases. c. Within a few years the population increases dramatically. d. The species' reproductive potential declines.

c. Within a few years the population increases dramatically.

Which of the following organisms has the highest reproductive potential? a. dogs b. elephants c. bacteria d. humans

c. bacteria

Thick fur on deer is not an example of coevolution. Why? a. because thick fur is an adaptation b. because deer with thick fur live longer c. because thick fur evolved in response to a cold climate, not in response to other organisms d. because in the lowlands, where the climate was sunny and warm, deer that did not have thick fur became separated from other deer that did have thick fur

c. because thick fur evolved in response to a cold climate, not in response to other organisms

If over a long period of time, each pair of adults in a population had only two offspring and the offspring lived to reproduce, the population would a. grow. b. shrink. c. remain the same. d. disperse randomly.

c. remain the same.

The ______ of an ecosystem for a particular species is the maximum population that the ecosystem can support indefinitely.

carrying capacity

A robin that does not affect the tree in which it nests is an example of ____

commensalism

A type of interaction between two species in which both species are harmed is ____.

competition

Competition for food cannot occur a. between two populations. b. among members of the same population. c. among populations whose niches overlap. d. between animals from two different ecosystems.

d. between animals from two different ecosystems.

In which of the following relationships is neither species harmed? a. predation b. competition c. parasitism d. commensalism

d. commensalism

Which of the following has the greatest effect on reproductive potential? a. producing more offspring at a time b. reproducing more often c. having a longer life span d. reproducing earlier in life

d. reproducing earlier in life

Which of the following populations has a random dispersion? a. flock of flamingoes b. pine trees in a pine fores c. herd of bisont d. solitary snakes in a desert

d. solitary snakes in a desert

The carrying capacity of an environment for a particular species at a particular time is determined by the a. number of individuals in the species. b. distribution of the population. c. reproductive potential of the species. d. supply of the most limited resources.

d. supply of the most limited resources.

A female dog's niche includes all of the following except a. fleas that infest the dog. b. the number of puppies the dog has. c. how the dog protects its owners. d. the neighbor's enclosed yard.

d. the neighbor's enclosed yard.

The density of a population is a. the number of individuals born every year. b. the proportion of males and females. c. the number of individuals living in cities. d. the number of individuals per unit area.

d. the number of individuals per unit area.

A population's ________ is usually described as even, clumped, or random.

dispersion

If a pair of mice finds a place to live with plenty of food and no predators, the population of mice will probably undergo ______ growth.

exponential

The organisms in a cow's stomach have a constant source of food; the organisms help the cow break down and use the grass it eats. This type of relationship is an example of _______.

mutualism

A population has a(n) _______ growth rate when the death rate is higher than the birth rate.

negative

A species' _____ includes that species' physical home, the environmental factors necessary for that species' survival, and all its interactions with other organisms.

niche

A liver fluke is a(n) _______ that harms its host as it obtains food.

parasite

A(n) ______ usually only weakens its host, while a(n) _____ usually kills its prey.

parasite, predator

The type of interaction between cats and mice is ______.

predation

The maximum number of offspring that each member of a population can produce is the population's ____

reproductive potential

A relationship in which two organisms live in close association, such as mutualism and commensalism, is called _____.

symbiosis