'23 Ecology: Bioenergetics, Biotic/Abiotic, Succession & Symbiosis

2 part question: What is the main difference between primary and secondary succession?

Which of the following best defines a niche in ecology?

• The total number of species in an ecosystem.
• The role or job and position of a species in its environment.
• The physical appearance of an organism.
• The process by which organisms evolve over time.

Since the early 2000s, sea-star-wasting disease has affected the purple sea star population along the West Coast of the United States. In the 1960s, ecologists did an experiment temporarily removing purple sea stars from a tide pool. During the experiment, the ecologists continually removed the sea stars from the tide pool for two years until their population was removed completely. Figure 1 shows the major organisms in the tide pool food web before the experiment, after one year, and after five years. Fill in the blanks with the word or phrase that supports the following claim: Ecologists claim that sea-star-wasting disease will severely disrupt the coastal ecosystem. The ___________ because __________________. Choose all correct answers.

• claim is refuted because species richness increased during the experiment.
• claim is supported because biodiversity remained low long after the sea stars were removed in the experiment.
• validity of the claim cannot be concluded because the coast is a much larger area than a tide pool.
• claim is refuted because the ecosystem remained stable after the sea stars were removed in the experiment.

Since the early 2000s, sea-star-wasting disease has affected the purple sea star population along the West Coast of the United States. In the 1960s, ecologists did an experiment temporarily removing purple sea stars from a tide pool. During the experiment, the ecologists continually removed the sea stars from the tide pool for two years until their population was removed completely. Figure 1 shows the major organisms in the tide pool food web before the experiment, after one year, and after five years. Fill in the blanks with the word or phrase that supports the following claim: What would have happened in the experiment if the ecologists had reintroduced purple sea stars to the tide pool at the end of five years?

• The new sea stars would die immediately due to lack of food.
• Lack of biodiversity would cause the ecosystem to fail to recover.
• The tide pool ecosystem would recover completely within a few years.
• Mussels would consume the sea stars and the ecosystem would not recover.

A limiting factor that depends on population size. (BI-LS2-6)

• hunting
• density-dependent factor
• niche
• commensalism

How much energy is lost between trophic levels? (BI-ESS2-4)

• 90%
• 10%
• 15%
• 25%

A symbiotic relationship in which both species benefit is _________. (BI-LS2-6)

• mutualism.
• predation.
• commensalism.
• parasitism.

Refer to the illustration below. Based on the pyramid which animal is shown as the secondary consumer? (BI-LS2-6)

• plant
• rat
• snake
• eagle

Which of the following has a one way path in the ecosystem? (BI-ESS2-4)

• nitrogen
• energy
• carbon
• water

An animal or plant that a parasite lives on or in. (BI-LS2-6)

• prey
• predator
• host
• initial species