BIOL 111G Mastering 11: Communities and Ecosystems

Caterpillars (1) eat passionflower leaves (2).

(1) + (2) + herbivory.

Honeybees (1) pollinate daisies (2) while feeding on their nectar and pollen.

(1) + (2) + mutualism

Unicellular algae (1) live inside corals (2).

(1) + (2) + mutualism

Fleas (1) feed on the blood of cats (2).

(1) + (2) - parasitism

Black rat snakes (1) eat rats (2).

(1) + (2) - predation

House sparrows (1) and house finches (2) require similar food and nest sites.

(1) - (2) - competition

Weeds (1) grow among tomato plants (2).

(1) - (2) - competition

10,000 kcal of producer could support approximately _____ kcal of tertiary consumer.

10

Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level.

5-10

In an ecosystem where 500,000 kcal of sunlight is available for producers, approximately how much chemical energy will be contained in secondary consumers?

50 kcal (This is approximately how much energy is contained in secondary consumers. About 10% of available biomass in primary consumers is converted to biomass in secondary consumers.)

Consider the following prairie food chain. Tall grass is consumed by grasshoppers that, in turn, are eaten by mice, and the mice are eaten by prairie kingsnakes. Red-tailed hawks prey on mice and prairie kingsnakes. When a red-tailed hawk dies, bacteria, beetles, fungi, and many types of worms help break down the body. Which of the following correctly identifies a trophic level in this ecosystem?

Grasshoppers are primary consumers. (Grasshoppers consume the producers and are therefore primary consumers.)

All the populations of organisms living close enough together for potential interaction make up __________.

a community (A community consists of all the populations of all the species found in a particular environment.)

Energy flow in an ecosystem is driven by (a) that moves through (b) and is released as (c). Trophic level 4 (d). Trophic level 3 (e). Trophic level 2 (f). (is captured and converted to chemical energy by/Trophic level 1) (g). Matter further broken down by (h).

a. solar energy b. trophic levels c. heat d. tertiary consumers e. secondary consumers f. primary consumers g. primary producers h. decomposers (Energy enters an ecosystem as sunlight (solar energy) and is transformed to chemical energy via photosynthesis by primary producers. The chemical energy is passed through the various levels of consumers, with much of the energy being lost as heat with each transfer.)

Most plants have a variety of chemicals, spines, and thorns because the plants

cannot run away from herbivores.

_____ are secondary consumers.

carnivores (Secondary consumers are animals that eat other animals; thus, they are carnivores.)

One predator avoidance mechanism that has evolved in prey is

chemical defenses and bright coloration.

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

competition

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

detritivore

Organisms that digest decaying organic material are

detritivores.

In most ecological communities, plants are the first level of the trophic structure, known as producers. What do plants produce that supports the higher trophic levels of the community?

energy-containing food molecules

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?

mutualism

When two different populations in a community benefit from their relationship with each other, the result is called

mutualism.

The freshwater leech is an organism that feeds off of the blood of other organisms such as frogs and turtles. Which interaction describes the relationship between freshwater leeches and frogs or turtles?

parasitism

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

parasitism

In an ecosystem, you would expect to find interspecific competition between

populations of two species that occupy the same niche.

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

predation

Camouflage typically evolves as a result of

predation.

A cow eating grass is an example of a _____.

primary consumer

In an ecosystem, phytoplankton are _____.

producers

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

secondary consumer

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

tertiary consumer

The main cause of the recent increase in the amount of carbon dioxide in Earth's atmosphere is __________.

the burning of larger amounts of wood and fossil fuels (There are not enough primary producers to keep up with the loading of carbon in the atmosphere from the burning of wood and fossil fuels.)