Ecology Test Review

Black ferns are a species of bird living in marshes, ponds and marshy lakes. They feed on insects, fish and crustaceans. They usually make their nests on loose, floating vegetation. Which of the following environmental changes would most likely decrease the size of the black tern populations? Select TWO correct answers.

• A new plant species invades the environment and creates a dense cover of vegetation.

• nsect larvae experience lower than average rates of predation and survive to adulthood.

• A competing bird population decreases in size.

• A disease affecting crustaceans decreases that population.

A student set up a compost bin outdoors. Inside the bin, microorganisms convert the student's vegetable and paper scraps into rich fertilizer. Which of the following best describes the role that these microorganisms play in natural habitats?

• The microorganisms help keep nutrients cycling through the ecosystem.

• The microorganisms turn solar energy into sugar.

• The microorganisms function as autotrophs.

• The microorganisms help balance the numbers of producers and consumers.

Scientists have observed many types of tropical fish moving beyond their traditional ocean ranges into waters that have historically been more temperate. These fish compete for food with native fish, consuming much from the kelp forests and beds of sea grass. The expansion of the ranges of tropical fish was most likely caused by —

• global droughts that raise the salt concentration of ocean waters

• agricultural runoff that contributes to dead zones in the ocean

• the rising temperatures of ocean waters

• acid rain pollution that lowers the pH of ocean waters

In a forest, how do decomposers help other organisms survive?

• They recycle nutrients into the soil that plants use to grow.

• They provide shelter in the forest where animals can hide.

• They use sunlight to make food for plants and animals

• They release oxygen into the air that animals breathe.

Which answer choice best describes a community?

• Three-spined sticklebacks living in estuaries

• Praying mantises caring for their young

• Roosting mother bats recognizing their offspring

• Different species of lizards occupying the same niche in a desert

Which of the following events would lead to primary succession?

• Deforestation by loggers on private land

• A volcanic eruption that expands the Hawaiian Islands

• A forest fire sweeping through a national park

• A lightning strike causing a fire to burn acres of grasslands

The diagram shows a partial East Texas food web. Which table correctly classifies these organisms?

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Surtsey is an island located south of Iceland. The island was formed by a volcanic eruption and first appeared in 1963. The table below contains descriptions of changes in the population and diversity of species on Surtsey. Which of these lists shown above lists the descriptions in the correct order of ecological succession on Surtsey?

• IV, III, I, II

• III, I, II, IV

• I, II, IV, III

• II, IV, I, III

A remora is a fish that has an adhesive disk on the back of its head that it uses to attach itself to a large shark. When food floats away from the shark’s mouth as it feeds, the remora collects the scraps. Drawings of a shark with a remora attached and a remora’s adhesive disk are shown below. The relationship between the remora and the shark is an example of —

• parasitism

• predation

• competition

• commensalism

This picture represents a body of water changing from a lake to a marsh over several hundreds of years. The picture is a representation of-

• Competition

• Succession

• Commensalism

• Habitat destruction