Biomes

Which of the following occurs when bacteria break down organic matter and return carbon dioxide and water to the environment?

• combustion
• transpiration
• nitrogen fixation
• decomposition

Clouds form in the atmosphere through the process of

• precipitation
• respiration
• condensation
• decomposition

Bacteria are most important in the process of

• combustion
• condensation
• nitrogen fixation
• evaporation

Which of the following is a biotic factor in a biome?

• the quality of soil
• the amount of rainfall
• the presence of lakes and ponds
• the kinds of grasses

Which of the following is NOT a key abiotic factor in marine ecosystems?

• water temperature
• water depths
• amount of sunlight
• amount of plankton

An ecosystem with wet soil, willow trees, and orchids is likely

• a marsh
• a swamp
• a forest
• a pond

The base of the ocean’s food chains is formed by

• blue whales
• coral reefs
• plankton
• sargassums

Which of the following is an abiotic factor in a biome?

• the kinds of trees
• the number of insect species
• the average temperature
• the mosses and algae

Which of the following statements about groundwater is true?

• It stays underground for a few days.
• It is stored in underground caverns or porous rock.
• It is salty like ocean water.
• It never re-enters the water cycle.

Water temperature

• has no effect on the animals in a marine ecosystem.
• affects the types of organisms that can live in a marine ecosystem.
• decreases gradually as water gets deeper.
• increases as water gets deeper.