Ecology Review

Ecology Review

Food Chains and Food Webs

• Food Chain = series of steps in an ecosystem in which organisms transfer energy by eating and being eaten.

• Food web = network of all the food chains formed among the various organisms in an ecosystem.

• The arrow shows the direction of energy flow.

Multiple Choice

A food chain is represented below.

grass --> rabbit --> hawk

Structures within the rabbit are formed using

• solar energy from the grass

• heat energy lost to the environment

• chemical energy from the hawk

• chemical energy from the grass

Multiple Choice

The diagram below represents a food chain made up of organisms found in a field. Which row in the chart correctly identifies characteristics that can be associated with the members of this food chain?

• 1

• 2

• 3

• 4

Multiple Choice

A food web is represented in the diagram below. If the fish population decreases, what is the most direct effect this will have on the aquatic ecosystem?

• The leopard seals will all die from lack of food.

• The krill population will only be consumed by seagulls.

• The zooplankton population will increase in size.

• The phytoplankton population will increase in size.

Energy Pyramids

• shows the relative amounts of energy at each trophic level.

• shows the relative population at each trophic level. 

• As you go up the pyramid the amount of energy decreases.

• As you go up the pyramid the population size decreases.

• Energy is used or lost as heat.

Multiple Choice

Some organisms in an ecosystem are represented in the pyramid below. In the pyramid, the arrows labeled X represent

• the loss of organisms due to predation

• a decrease in photosynthetic organisms

• the loss of energy in the form of heat

• a decrease in available oxygen

Multiple Choice

The diagram below represents an energy pyramid. Which type of organism could occupy levels B, C, and D of this energy pyramid?

• consumer

• producer

• autotroph

• carnivore

Ecological Relationships

• Symbiosis = the relationship between 2 different organisms living together

• Parasitism = one organism benefits while the other is harmed (+/-)

• Mutualism = both organisms benefit (+/+)

• Commensalism = one organism benefits while the other is neutral (+/0)

Multiple Choice

Sea anemones are mainly sessile animals. Some of them depend on the motile clown fish for their survival. The clown fish helps to provide food for the sea anemone as it seeks protection in the anemone's tentacles. This symbiotic relationship is known as

• commensalism

• saprophytism

• mutualism

• parasitism

Multiple Choice

In which symbiotic relationship do two different species benefit from their association with one another?

• saprophytism

• commensalism

• mutualism

• parasitism

Population Graphs

• Popluation graphs display patterns that are used to

• 1) study relationships in an ecosystem

• 2) make predictions about the fate of populations

Multiple Choice

The graph below shows changes in the populations of hares and lynx in a Canadian ecosystem. Which statement about the hares and lynx can be supported with information from the graph?

• The hare is the predator of the lynx because it is a larger animal.

• The lynx population begins to drop after the hare population drops.

• Both populations go through cycles due to the succession of plant species.

• Both populations have a carrying capacity of 3000 per square kilometer.

Multiple Choice

Base your answer on the graph below which shows the population growth curves of Paramecium aurelia and Paramecium caudatum cultures after they were mixed together. This graph can be used to illustrate the principle of

• carrying capacity

• competition

• predator-prey relationship

• mutualism

Multiple Choice

Changes in a deer population are shown in the graph below. Which statement best explains section X?

• The population has reached the carrying capacity of its environment.

• Energy is used for interbreeding between members of different species.

• A predator recycles the remains of dead organisms.

• Competition does not occur between members of different species in the same habitat

Biodiversity & Invasive Species

• Biodiversity = a variety of different living organisms in an ecosystem

• The more biodiverse an ecosystem, the more stable the ecosystem is.

• Invasive species are a threat to biodiversity

• Invasive species outcompete native species for resources

• reproduce rapidly

• feed on anything

• do not have natural predators to keep the population in check

Multiple Choice

Cutting down a rain forest and planting agricultural crops, such as coffee plants, would most likely result in

• a decrease in biodiversity

• an increase in the amount of energy recycled

• a decrease in erosion

• an increase in the amount of photosynthesis

Multiple Choice

An ecosystem will most likely remain stable if

• it has more predators than prey

• it has a high level of biodiversity

• biotic factors decrease

• finite resources decrease

Multiple Choice

In 1960, an invasive species of fish was introduced into the stable ecosystem of a river. Since then, the population of a native fish species has declined. This situation is an example of an

• ecosystem that has recovered

• ecosystem altered through the activities of an organism

• environmental impact caused by physical factors

• ecological niche without competition

Ecological Succession

• The natural, gradual development of a stable ecosystem over time

• Each stage of ecological succession modifies the environment for the next stage

• The climax community is the final stage of ecological succession (lots of biodiversity, and very stable)

• Primary Succession = succession in an area where a community didn't exist before (starts with rock, barren)

• Secondary Succession = succession in an area where a disturbance destroyed existing community (soil is present)

Multiple Choice

In December 2004, a tsunami (giant wave) destroyed many of the marine organisms along the coast of the Indian Ocean. What can be expected to happen to the ecosystem that was most severely hit by the tsunami?

• The ecosystem will change until a new stable community is established.

• Succession will continue in the ecosystem until one species of marine organism is established.

• Ecological succession will no longer occur in this marine ecosystem.

• The organisms in the ecosystem will become extinct.

Multiple Choice

The stable stage that is established in an area as a result of the process of ecological succession is known as the

• heterotroph community

• pioneer stage

• climax community

• biotic community

Multiple Choice

The diagram below represents the stages of ecological succession in New York State. The stages are not in order. Which sequence represents a correct order of succession that would involve these stages?

• 2 --> 3 --> 1 --> 4 --> 5

• 2 --> 1 --> 3 --> 5 --> 4

• 3 --> 1 --> 2 --> 4 --> 5

• 3 --> 2 --> 1 --> 5 --> 4

Cycles

• The water cycle = the continuous movement of water above, on or below the surface of the Earth.

• The carbon cycle = nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again

• The carbon cycle is controlly mainly by the processes of photosynthesis and cellular respiration

Multiple Choice

The diagram below represents a cycling of materials. Which row in the chart below shows the substances represented by X and Y?

• 1

• 2

• 3

• 4

Multiple Choice

Which two life functions of animals help maintain the water cycle by recycling water back into the environment?

• digestion and regulation

• synthesis and locomotion

• respiration and excretion

• respiration and photosynthesis

The End!

STUDY!!!! ;-)