SCI 101-Chapter 20 Worksheet

Part 1

Multiple choice

Directions: Read each statement or question below carefully and select the answer that best fits the question.

1. Decomposers are associated with which class of food web?

1. grazing
2. detrital
3. inverted
4. aquatic
5. The producer in an ocean grazing food web is usually a ________.

1. plant
2. animal
3. fungi
4. plankton
5. Which term describes the process whereby toxic substances increase along trophic levels of an ecosystem?

1. biomassification
2. biomagnification
3. bioentropy
4. heterotrophy
5. The majority of the water found on Earth is:

1. ice
2. water vapor
3. fresh water
4. salt water
5. The process whereby oxygen is depleted by the growth of microorganisms due to excess nutrients in aquatic systems is called ________.

1. dead zoning
2. eutrophication
3. retrophication
4. depletion
5. Which of the following biomes is characterized by abundant water resources?

1. deserts
2. boreal forests
3. savanna
4. tropical wet forests
5. Which of the following biomes is characterized by short growing seasons?

1. deserts
2. tropical wet forests
3. Arctic tundra
4. savanna
5. Why is the tundra treeless?

1. lack of sufficient water
2. permanently frozen ground
3. winters too harsh
4. too many fires
5. Where would you expect to find the most photosynthesis in an ocean biome?

1. aphotic zone
2. abyssal zone
3. benthic realm
4. intertidal zone
5. A key feature of estuaries is

1. low light conditions and high productivity
2. salt water and fresh water
3. frequent algal blooms
4. little or no vegetation

Part 2

Short answer

Directions:Answer each question to the best of ability in the space provided. Spelling and syntax will be graded carefully.

1. Compare grazing and detrital food webs. Why would they both be present in the same ecosystem?

1. Why are drinking water supplies still a major concern for many countries?

1. The extremely low precipitation of subtropical desert biomes might lead one to expect fire to be a major disturbance factor; however, fire is more common in the temperate grassland biome than in the subtropical desert biome. Why is this?

1. In what ways are the subtropical desert and the Arctic tundra similar?

1. Describe the conditions and challenges facing organisms living in the intertidal zone.