ENSC 101 Exam 2
The pollination of flowering pants by species such as honeybees is
Mutualism
What is said to occur when one organism feeds on another organism by living on or in the other organism?
Parasitism
What refers to the ability of a living system to be restored after a period of moderate to severe disturbance?
Resilience
If the resilience of a damaged ecosystem is low enough, the degraded area may not be restored by secondary succession. When this happens, the damaged ecosystem has reached
a tipping point
The situation in which one set of species makes an area suitable for species with different niche requirements and often less suitable for itself is called
facilitation
The capacity to withstand external stress and disturbance is called ____.
stability
Late successional plants are largely unaffected by plants at earlier stages of succession because they are not in direct competition for resources, a factor called
tolerance
A group of interbreeding individuals of the same species in the same geographic region is called a(n) _____.
population
Parasites
rarely kill their hosts
What is the number of individuals in a population found within a defined area or volume that can limit the size of some populations?
population density
Species with a capacity for a high rate of population growth are called ____.
r-selected species
Each population in an ecosystem has a ____ to variations in its physical and chemical environment.
range of tolerance
Which of the following exhibits secondary ecological succession?
recently flooded land
If multiple species find themselves competing for the same resource, the competition can be reduced by which of the following?
resource partioning
Through natural selection, different species of birds called honeycreepers have shared resources by evolving specialized beaks to take advantage of certain types of food such as insects, seeds, fruits, and nectars from certain flowers. This is called
resource partioning
Kelp forests play key roles in marine ecosystems, in part by supporting important biodiversity. These kelp forests are threatened by
sea urchins
Kelp forests are composed of large concentrations of
seaweed
What type of succession begins in an area where an ecosystem has been disturbed, removed, or destroyed, and that contains soil or bottom sediment?
secondary succession
At the population level, parasites are always harmful to the host species.
False
Humans are exempt from population overshoot and dieback.
False
Organisms with clumped distributions are fairly rare.
False
The growth rate of a population increases as its size nears the carrying capacity of its environment.
False
The most common interaction between species is commensalism.
False
Animal predators tend to kill the sick, weak, aged, and least fit members of a species because they are the easiest to catch.
True
Humans compete with many other species for space, food, and other resources.
True
In communities and ecosystems the types and numbers of species change in response to changing environmental conditions.
True
In predator-prey relationships, the predator is seeking food for itself and its offspring, while the prey is seeking not to become food for the predator. As a result, predator and prey populations exert tremendous natural selection pressures on each other.
True
Large mammals, such as elephants and rhinoceroses, are especially vulnerable to extinction because of their reproductive patterns.
True
Populations of most plants and animals depend, directly or indirectly, on solar energy.
True
Primary and secondary ecological successions tend to increase biodiversity of communities and ecosystems by increasing species richness and interactions among species.
True
Scientists have changed their view about a stable type of climax community as the end product of succession and are now suggesting that we cannot predict the course of succession.
True
The carrying capacity of any given area is not fixed.
True
grasslands have a high resilience and therefore can quickly recover following a fire
True
Most ecologists now recognize that mature, late-successional ecosystems ____.
are in a state of continual disturbance and change
Some species that tend to reproduce later in life and have a small number of offspring with long life spans ____.
are vulnerable to extinction
The nonpoisonous ____ butterfly gains protection by looking like the bad-tasting ____ butterfly, which is a protective device known as ____.
viceroy; monarch; mimicry
What is an example of a K-selected species?
whales
Which of the following exhibits primary succession?
A rock exposed by a retreating glacier
Some prey species discourage predators with chemicals that are poisonous, irritating, foul smelling, or bad tasting. What is this called?
Chemical Warfare
What is the most common distribution of populations?
Clumped
What occurs when an interaction benefits one species but has little, if any, effect in the other?
Commensalism
What is the most common interaction between species?
Competition
The hind wings of Io moth resemble eyes of a much large animal. What is this called?
Deceptive looks
Describe what happens when species partition resources.
Resource partioning occurs when species competing for similar scarce resources evolve specialized traits that allow them to share resources by using parts of them, using them at different times, or using them in different ways.
Kelp forests help reduce ____ by blunting the force of incoming waves and trapping some of the outgoing sand.
Shore erosion
An example of a internal parasite is a
TAPEWORM
What was the primary reason the southern sea otter nearly went extinct in the early 1900's?
They had thick, luxurious fur.
What is a feature of r-selected species?
They have populations that fluctuate between high and low.
There are ___ limits to population growth in nature.
always
The primary reason the southern sea otter recovery is ecologically important is because they
are a keystone species
The maximum population of a given species that a particular habitat can sustain indefinitely is the definition of ___.
carrying capacity
Bats prey on certain species of moths by using high-frequency echolocation to locate them. Certain moths have evolved ears that can hear these frequencies allowing them to escape. This is an example of
coevolution
When populations of two different species interact over long periods of time, changes in the gene pool of one species can lead to changes in the gene pool of the other. What is this called?
coevolution
When plotting the number of individuals in a population against time, the data yield a J-shaped curve. What does this curve indicate?
exponential growth
Emigration is the ____.
departure movement of individuals from a population to another area
Plants such as pitcher plants share a commensalistic interaction with large trees in tropical and subtropical forests by attaching to the trunks or branches of the trees. The pitcher plants are examples of
epiphytes
By 1900, white-tailed deer populations in the United States were drastically reduced, but now, since laws have been passed to protect them and their natural predators, their population has ____.
exploded
A population increases through birth and ____.
immigration
The ability of a living system to survive moderate disturbances is called
inertia
What occurs when members of two or more species interact to gain access to the same limited resources?
interspecific competition
Too much or too little of any physical or chemical factor can prevent the growth of a population, even if all other factors are at or near the optimum conditions. What is this ecological principle?
limiting factor
Exponential growth followed by a steady decrease in population growth until the population size stabilizes is typical of ____.
logistic growth
Grasslands have ____ and can burn easily.
low inertia
The relationship between clown fish and sea anemone is called
mutualism
When two species behave in ways that benefit both by providing each with food, shelter, or some other rescue. It's called
mutualism
What has caused the population of the southern sea otters to fluctuate?
parasites that breed in cats
