The limitations of ecological pyramids include all the following except:

1. The do not take into account the same species belonging to two or more trophic levels

2. They do not represent relationships between organisms at different trophic levels

3. They assume a simple food chain and do not consider food webs

4. Saprotrophs are not given any place in the ecological pyramids

About what percent of the global carbon is contained in the atmosphere?

1. 71

2. 49

3. 17

4. about 1

Which of the following organisms will be the first to colonize a bare rock?

1. Annual plants

2. Lichens

3. Perennail plants

4. Herbs and shrubs

Most food chains are composed of 

1. 1 or 2 species

2. 3 or 4 species

3. 9 or 10 species

4. More than 16 species

The phosphorus cycle is unusual in that it is entirely:

1. Within aquatic ecosystems

2. Within terrestrial ecosystems

3. Sedimentary

4. Gaseous

Most primary productivity in the surface water of lakes and oceans is by:
1. Floating plants
2. Red and brown algae
3. Zooplankton
4. Phytoplankton

During ecological succession

(1) the gradual and predictable change in species composition occurs in a given area

(2) the establishment of a new biotic community is very fast in its primary phase

(3) the numbers and types of animals remain constant

(4) the changes lead to a community that is in near equilibrium with the environment and is called pioneer community

Which ecosystem has the maximum biomass?

(1) Forest ecosystem 

(2) Grassland ecosystem 

(3) Pond ecosystem 

(4) Lake ecosystem 

Th primary producers of the deep-sea hydrothermal vent ecosystem are

(1) green algae

(2) chemosynthetic bacteria

(3) blue-green algae

(4) coral reefs

Which one of the following is a characteristic feature of cropland ecosystem?

(1) Least genetic diversity

(2) The absence of weeds

(3) Ecological succession

(4) The absence of soil organisms