Ecology/Evolution

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

In this pyramid, the greatest amount of stored energy is found at level

• A

• B

• C

• D

When handling cat litter, humans can potentially be exposed to a harmful single-celled protozoan. Its primary host is the common domestic cat, but it can also live in humans. This protozoan is an example of a

• Predator

• Producer

• Parasite

• Scavenger

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.

Which group of organisms in an ecosystem fills the niche of recycling organic matter back to the environment?

• carnivores

• decomposers

• producers

• predators

In a sewage treatment facility, an optimal environment is maintained for the survival of naturally occurring species of microorganisms. These organisms can then break the sewage down into relatively harmless wastewater. For these microorganisms, the wastewater facility serves as

• its carrying capacity

• food chain

• ecosystem

• energy pyramid

Energy in this ecosystem passes directly from the Sun to

• herbivores

• consumers

• heterotrophs

• autotrophs

Two carnivores in the food web are

• bass and small invertebrates

• small invertebrates and crabs

• water plants and clams

• crabs and crayfish

Dodder plants consist of tangled masses of yellow, leafless vines and contain few chloroplasts. The vines twist around and grow into the stems of other plants and absorb water and nutrients from them. Which statement best describes this relationship?

• Dodder plants are parasitic, relying on host organisms for resources.

• Dodder plants are decomposers, returning organic material back to the environment.

• Dodder plants are producers, while the other plants that they attach to are consumers.

• Dodder plants are consumers, transferring energy to other plants in the ecosystem.

Which statement is correct, based on the information in the diagram?

• Salmon are predators of sea lampreys.

• Plankton decompose salmon and sculpins.

• Cormorants and sea lampreys compete for bacteria.

• Lake trout and salmon compete for sculpins.