Exam 37: Communities and Ecosystems

One simple thing that you can do to help safeguard the environment is to eat a diet consisting only of organisms that are

An owl and a hawk both eat mice. Which of the following describes the relationship between a hawk and an owl?

After reading the paragraphs below, answer the questions that follow. Biosphere II is a huge dome-covered self-contained structure located outside Tucson, Arizona. It was built to try to duplicate Earth's biosphere and ecosystems in miniature and to use the information gained from the experiment to help design similar habitats on the Moon and Mars. The habitat contained small versions of many of Earth's ecosystems, including an ocean with a coral reef, mangrove wetlands, a grassland, a desert, an agricultural system, and a human habitat. Eight men and women were sealed inside the habitat for a proposed two-year stay. The air, water, and food for the "biospherians" all came from inside the sealed habitat, and their only contact with the outside was through computers and telephones. Before the two years were up, however, the experiment failed. Supplemental oxygen was pumped into the facility, and food supplies were provided through the airlocks. What caused the failure of the experiment? It was traced to nutrient pollution. The soil in some of the biosphere ecosystems was unusually rich in nutrients. These excess nutrients caused a huge population explosion in decomposer bacteria, which led to oxygen depletion. -To stabilize the environment in the habitat and enable it to become self-sufficient again, it would be helpful to

After reading the paragraph below, answer the question that follows. A stonefly is an aquatic insect that has an incomplete life cycle. It spends its growing period (nymph life stage) on the bottom of streams, camouflaged by the rocky bottom. When it has finished growing, it crawls to the edges of streambeds to molt and emerges as a winged adult. Fish often eat the juvenile nymphs as they make their way to the edge of the streambeds. -Suppose that scientists who study predator-prey relationships notice that over a 50-year span, new color patterns evolve in the stonefly nymphs such that they are better able to blend into the colors of a streambed. What would be a logical and reasonable question that the scientists could investigate in relation to their observations and their knowledge of predator-prey relationships?

Denitrifying bacteria convert ________ to ________.

Dinoflagellates are important to coral and coral-dwelling animals because they

What are the consequences if decomposers are removed from the carbon cycle?

For a given area and time period, the amount of solar energy converted to chemical energy in organic compounds is called

The number of species in a community is called the

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

After reading the paragraphs below, answer the questions that follow. Biosphere II is a huge dome-covered self-contained structure located outside Tucson, Arizona. It was built to try to duplicate Earth's biosphere and ecosystems in miniature and to use the information gained from the experiment to help design similar habitats on the Moon and Mars. The habitat contained small versions of many of Earth's ecosystems, including an ocean with a coral reef, mangrove wetlands, a grassland, a desert, an agricultural system, and a human habitat. Eight men and women were sealed inside the habitat for a proposed two-year stay. The air, water, and food for the "biospherians" all came from inside the sealed habitat, and their only contact with the outside was through computers and telephones. Before the two years were up, however, the experiment failed. Supplemental oxygen was pumped into the facility, and food supplies were provided through the airlocks. What caused the failure of the experiment? It was traced to nutrient pollution. The soil in some of the biosphere ecosystems was unusually rich in nutrients. These excess nutrients caused a huge population explosion in decomposer bacteria, which led to oxygen depletion. -How could a population explosion of bacteria lead to oxygen depletion?

Which of the following substances is cycled between organic matter and abiotic reservoirs?

Organisms that digest molecules in organic material and convert them into inorganic forms are

Which of the following statements about the nitrogen cycle is true?

When a New England farm is abandoned, its formerly plowed fields first become weedy meadows, then shrubby areas, and finally forest. This sequence of plant communities is an example of

The prokaryotes that cause tooth decay have a ________ relationship with humans.

In a food chain consisting of phytoplankton → zooplankton → fish → fishermen, the fishermen are

Non-native species that are introduced to new environments, spread far beyond the original point of introduction, and cause damage are called

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

After reading the paragraph below, answer the questions that follow. Consider the following marine community: Sea otters prey on sea urchins and therefore help maintain a healthy sea urchin population. Sea urchins prey on kelp. By helping to maintain viable sea urchin populations, the sea otters are also allowing enough kelp to grow and act as a habitat for other organisms. -Suppose that a bacterial infection swept across a sea otter population and killed most sea otters before they could reproduce. How would the marine community be affected?