Ecology Review - Bio

One characteristic of a stable ecosystem is

• a high number of predators

• an interdependence of organisms

• a lack of biodiversity

• an increase in human interference

The organisms in a pond and the physical factors influencing them best describe

• a population

• an ecosystem

• a biosphere

• a food chain

Populations of aspen trees in the western United States are being destroyed by an unexplained illness. The altered landscape is affecting the animals that live there. Populations of deer mice are increasing greatly in these areas. Unfortunately, these mice often carry a virus that is deadly to humans. This scenario best illustrates that

• a change in the environment always results in disease

• humans are the cause of the breakdown of this ecosystem

• the stability of this ecosystem is limited by the amount of water available

• every population in an ecosystem is linked with other populations

A fundamental concept of ecology is that living organisms

• are independent and do not interact with each other or with the physical environment.

• do not interact with other living organisms, but do interact with the physical environment

• interact with each other, but do not interact with the physical environment

• interact with other living organisms and interact with the physical environment

Many biotic factors affect individuals in a population. An example of an organism being directly affected by a biotic factor is

• a squirrel cannot find a mate

• a flood washes away a maple tree

• a plant is in a dark room

• a chipmunk finds a rock pile to use for a home

A finite resource in the environment that keeps a population from steadily increasing is known as

• dynamic equilibrium

• a limiting factor

• a reproductive enzyme

• ecological succession

Members of a bird-watching club observed the activities of three species of birds for an entire spring and summer. They noticed that the different species fed at different heights in the same pine tree. Which ecological concept is supported by this observation?

• Organisms that feed on different foods in the same area of an ecosystem fill the same niche.

• Organisms that live in the same ecosystem can occupy different niches in the ecosystem.

• Different species feeding in the same ecosystem will eventually compete with each other, eliminating all the species except one.

• Different species living in the same area of an ecosystem usually have the same physical characteristics.

The bar graph below shows the number of species in four pond ecosystems. Which ecosystem is likely to be the most stable?

• A

• B

• C

• D

Deer ticks are responsible for spreading Lyme disease. This organism, which feeds on the blood of warm-blooded organisms like mice, deer, and humans, is best described as a

• predator

• scavenger

• parasite

• host

A factor not shown in the diagram that provides energy for living organisms is

• carbond dioxide

• water

• the sun

• oxygen