bio chap 53/54 homework

A cow eating grass is an example of a _____.

By feeding on a producer, the cow is acting as a primary consumer.

Which of the following statements about density-independent growth is true?

Density-independent growth is also known as exponential growth.

Which of the following statements about a population experiencing logistic growth is true?

If N is greater than K, the population will shrink This statement is true, since K is the maximum number of individuals that can be supported in a particular habitat over a sustained period of time.

Humans who have pets tend to be healthier than humans who do not have pets. Which of these terms applies to the relationship between a human and a pet?

In mutualism, both members of the species pair benefit; in this case the human is healthier and the pet is getting room and board.

In the models that describe population growth, r stands for _____.

R = per capita population growth rate the growth rate of a population is represented by r, which is equal to the per capita birth rate minus per capita death rate

A human who just ate a hamburger is eaten by a shark while swimming. The shark is acting as a _____.

The shark that ate the human that ate the cow that ate the grass is the tertiary consumer.

Caribbean coral reef communities have been strongly influenced by an unknown pathogen that causes white-band disease. How can the effect of white-band disease best be described?

a cascade event that shifts the entire make up of the community the removal of the coral shifts the food supply within the reef, resulting in a completely different species composition

Which of the following is an example of a population?

all of the redwood trees that live in a forest This includes the individuals of one species in one place that presumably interact, use the same resources, and are influenced by the same environmental conditions.

Which of the following statements are true of logistic growth?

b. As the population approaches carrying capacity, it grows more slowly. d. When the population reaches carrying capacity, it stops growing.

Of the choices below, which best describes the effect predation has on the predator/prey organisms involved in the relationship?

benefit... harmed the predator eats ( a benefit ) and the prey is eaten ( a harm )

Which of the following factors does not contribute to environmental resistance? birth rate environmental toxins competition for food competition for space weather conditions

birth rate

Which processes increase a population's size?

births and immigration Immigration is the movement of individuals into a population, so births and immigration increase a populations size

mutualism -

both members of the species pair benefit,

In wild populations, individuals most often show a _____ pattern of dispersion.

clumped individuals are often found clumped because they are interacting are attracted to areas that provide the most favorable environmental conditions

An egret eats insects stirred up by grazing animals. Which of these terms applies to the relationship between the egret and the grazing animal?

commensalism In commensalism, one member of the species pair benefits and the other is unaffected; in this case the egret is getting a meal and the grazing animals are unaffected.

Humans and sharks both eat fish. Which of these terms applies to the relationship between the human and the shark?

competition The human and the shark are both competing for a resource (fish).

An earthworm that feeds on the remains of plants and animals is acting as a _____.

detritivore the earthworm is feeding on the rains of dead organisms - detritivore

According to the principle of competitive exclusion, two species cannot continue to occupy the same _____.

ecological niche the competitive exclusion principal states that when populations of two species compete for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other species

as a population approaches carrying capacity, environmental resistance ______

increases

An organism's "trophic level" refers to _____.

its food source meaning , an organisms trophic level is determined by what it eats

Which of the following conditions favors "big-bang" reproduction?

low rates of offspring survival if the probability of any one offspring surviving is low, then parental fitness is enhanced by maximizing the offspring production

a populations carrying capacity

may change as environmental conditions change def; carrying capacity - largest number of individuals of a population that a given environment can support

Scientific study of the population cycles of the snowshoe hare and its predator, the lynx, has revealed that

multiple biotic and abiotic factors contribute to the cycling of the hare and lynx populations.

Cellulose-digesting microorganisms live in the guts of termites and ruminant mammals. The microorganisms have a home and food, and their hosts gain more nutrition from their meals. This relationship is an example of _____.

mutualism

commensalism

one member of the species pair benefits and the other is unaffected

Which of these terms applies to the relationship between a dog and a blood-sucking tick?

parasitism the tick benefits at the expense of the dog , the dog is the host and the tick is the parasite

A human eats a deer. Which of these terms applies to the relationship between the human and the deer?

predation The human is the predator and the deer is the prey.

In an ecosystem, phytoplankton are _____.

producers - Autotrophs, such as phytoplankton, are producers.

When a human eats a steak, the human is acting as a _____.

secondary consumer - by feeding on a primary consumer the human is acting as a secondary consumer

Which factor does not affect a habitat's carrying capacity? Availability of food. Maximum number of individuals in a population. Intensity of predation. Number of nesting sites.

the maximum number of individuals in a population that can be sustained in a habitat over a period of time is the carrying capacity of a habitat

To determine the density of a rabbit population, you would need to know the number of rabbits and _____. To

the size of the area in which they live Density is the number of individuals of population per unit area

The feeding relationships among the species in a community determine the community's

trophic structure

The principle of competitive exclusion states that

two species that have exactly the same niche cannot coexist in a community

Keystone species are those species _____.

whose absence would cause major disruption in a community - a keystone species makes an unusually strong impact on community structure -A species that is not usually abundant in a community yet exerts strong control on community structure by the nature of its ecological role or niche.

Under which of the following conditions would a population most likely experience exponential growth?

young populations with few individuals meaning - young populations with few individuals are more likely to experience exponential growth because they have not used up the supply of resources

Which equation represents the logistic growth rate of a population?

ΔNΔt=rmaxN(K−N)K this equation represents the logistic growth rate of a population

Which of the following statements are true of a population at carrying capacity?

- The population growth rate equals zero -the rate at which resources are used is equal to the rate at which they are supplied -the birth rate equals the death rate

True or false? Factors that determine the per capita rate of increase of a population include the age of breeding and the number of offspring produced each year.

true - the per capita rate of increase of a population is the difference between the *per capita birth rate* and the *per capita death rate* , and is determined by factors that include the age of breeding and the number of offspring produced each year