An ecosystem consists of a community of organisms in a physical environment.
True
Almost all terrestrial ecosystems depend on the ability of plants to capture energy from the ______ and store it in complex organic molecules.
Sun
In ecosystems with enclosed canopies, the most intense competition among plants is likely to be for ___________.
Light
Competition occurs when plants of the same or different species attempt to use a resource that is in limited supply.
True
If new species attempt to colonize an ecosystem but lack open niches or unexploited resources, the result is known as ____________.
Exclusion
Plants that colonize niches in crop ecosystems are known as ____________.
Weeds
Parasites differ from herbivores because they cause ____________ rather than simply eating their way through plant tissues.
Diseases
Which of the following is an example of a biocontrol administered into a field of sweet corn?
Parasitoids
Mycorrhizae and Lichens are examples of symbionts.
True
What is added to crop ecosystems that relegate saprophytes and detritivores unnecessary?
Pesticides
When explorer Alexander von Humboldt moved north or south from the equator or ascended in altitude in different parts of the world, he noticed that there was a similar progression of vegetative types and climatic conditions. Today, we call the recurrent vegetation and climatic condition types ______.
Biomes
Natural ecosystems are known to be highly conservative regarding nutrients.
True
In the food web of a natural ecosystem, plants are known as _____________.
Producers
______________ is the main influence on the type of vegetation that develops.
Climate
Soils are produced from parent material by the interaction of climate and bacteria.
False
______________ availability is primarily affected by patterns of air circulation around the globe.
Moisture
In general, surface winds from latitudes 30o N and 30oS travel away from the equator.
False
Surface winds at these latitudes travel toward the equator.
At the ______________, temperatures are high throughout the year.
Equator
The roots of ____________ never reach bare mineral soil.
Epiphytes
The tropical rainforests of South America, Africa, India and southern Florida make up the most productive biome and largest range of biological diversity on earth.
True
Low temperature can be overcome more easily than lack of water for crop production.
False
Lack of water can be overcome more easily than low temperatures for crop production.
Net primary productivity or NPP is ____________ fixed minus the amount consumed by the plant.
Carbon
All locations in a geographic area tend to develop __________________ kinds of vegetation over time.
Same
The THEORETICAL end point of ecological succession is known as the _______________________.
Climax Community
