Question

in a food chain consisting of phytoplankton → zooplankton → fish → fishermen, the fishermen are
secondary consumers
tertiary consumers
quaternary consumers
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
trophic chain
secondary succession
primary succession
biological control is defined as *
the use of chemicals, such as pesticides, to control pests.
the intentional release of a natural enemy of a pest population.
an intentional attempt to increase the numbers of specific prey populations.
in an average ecosystem, about how much energy is available to the next higher trophic level?

Explanation:

• First Question:
• Phytoplankton are producers (first trophic level).
• Zooplankton eat phytoplankton (primary consumers, second trophic level).
• Fish eat zooplankton (secondary consumers, third trophic level).
• Fishermen eat fish (quaternary consumers, fourth trophic level).
• Second Question:
• Trophic chain is about energy transfer between organisms.
• Primary succession occurs on bare rock or new land.
• Secondary succession happens on previously occupied land (like abandoned farmland).
• Third Question:
• Biological control uses natural enemies (not chemicals) to control pests.
• Fourth Question:
• In an ecosystem, about 10% of energy is passed to the next trophic level (10% rule).

Answer:

• First Question: quaternary consumers
• Second Question: secondary succession
• Third Question: the intentional release of a natural enemy of a pest population
• Fourth Question: 10%