Unit 3 Review

At what level of organization in an ecosystem is an individual plant or animal?

• Population

• Organism

• Community

• Ecosystem

Ecosystem is the level of organization that is best described as including

• only a single individual of a single species plant or animal.

• two species that live in the same habitat and depend on each other

• all of the abiotic factors which characterize a geographic area.

• various species in an area and the abiotic factors on which they depend

Which of the following is an example of an interaction of a biotic factor with an abiotic factor in an ocean ecosystem?

• A sea turtle burying its eggs in sand

• A killer whale eating harbor seals

• Dolphins communication with each other

• A jellyfish staining its prey

Four species were introduced to a new ecosystem. The number of organisms for each population

for the first one hundred days are plotted in the graph below.

Which species was first to reach their carrying capacity?

• Species 1

• Species 2

• Species 3

• Species 4

An example of a predator and a prey species for four separate ecosystems is provided below.

Which of the following would demonstrate an appropriate prediction for the changes to one of

the populations of organisms due to a predator/prey interaction?

• When the population of sharks decreases because of fishing, the

  population of small fish will decrease.

• After a period of heavy rainfall and warmer temperatures, the population

  of mosquitos will increase.

• During hunting season, when many deer are killed by hunters, the

  mountain lion population will decline.

• When abundant resources allow the population of mice to increase, the population of

  snakes will decrease.

The relationships that organisms have with one another are an important part of the balance

among species within ecosystems. Which type of symbiotic relationship occurs when ecological

niches overlap, and multiple organisms seek the same resources?

• Parasitism

• Commensalism

• Predation

• Competition

Remoras are fish that attach themselves to the underside of larger organisms, such as sharks.

Which of the following observations best supports this relationship as an example of mutualism?

• Remoras get food by cleaning parasites from the sharks.

• Remoras sometimes associate with animals other than sharks.

• Remoras are capable of swimming on their own quite well.

• Like sharks, remoras reproduce by laying eggs.

Predation and parasitism are similar because in both predation and parasitism

• both organisms receive a benefit.

• one organism is harmed while the other benefits.

• one organism is neither harmed nor benefits.

• both organisms are harmed in some way.

The energy organisms need to live and grow first enters a lake ecosystem when

• plants take in radiant energy from the Sun.

• decomposers break down dead organisms.

• primary consumers eat plants for food.

• secondary consumers eat primary consumers.

Scientists studying two adjacent ecosystems observe different varieties of organisms in the two

areas. All of the following factors would contribute to the differing varieties of organisms in

these two habitats EXCEPT −

• climate.

• soil type.

• water resources.

• wind.