Unit 9: Organisms an the Environment

Which of the following situations contributes to the sustainability of an ecosystem?

• Decrease in biodiversity

• Increase in biodiversity

• Removal of many populations of organisms

• Extinction of a population from the ecosystem

The diagrams above show an ecosystem during different stages of ecological succession.

In which order will these stages occur, from earliest to latest?

• 1, 2, 3, 4

• 4, 3, 2, 1

• 4, 2, 1, 3

• 1, 3, 4, 2

The more diverse an ecosystem is —

• the more stable it is

• the more similar the species will be

• the fewer varieties of species are present

• the more threatened its populations are

If you were studying vegetation and animal life around a small pond, you would expect to find a greater variety of organisms —

• Area D

• Area C

• Area B

• Area A

Which statement below best describes how biodiversity contributes to the sustainability of an ecosystem?

• Having more species in an ecosystem allows the human population to increase in size.

• A variety of plant and animal species allows for more survivors of a natural disaster.

• Fewer species in the ecosystem reduces the likelihood that disease spreads through the ecosystem

• Low biodiversity reduces the competition for resources, which helps native species survive.

Which of the plants described above would most likely be found in the rainforest?

• leaves with dry tips, climbing vines and canopy covering

• grows in clumps, hairy leaves, small

• nonporous leaves, extended roots

• absence of trees

What effect does the increase in human population most likely have on the biodiversity of the plant species found in the rainforest?

• As human population increases, the succession in the rainforest leads to increased biodiversity.

• As human population increases, the diversity of all rainforest plant species decreases.

• As human population increases, the number of individual rainforest plant species increases.

• As human population increases, the diversity of larger rainforest plant species increases.

Which student best describes how microhabitats are able to support a variety of organisms?

• Student 1

• Student 2

• Student 3

• Student 4

Which statement best describes the comparison of lake and ocean environments?

• The lake and ocean environments support the same organisms, but they will look different because of the type of water.

• The lake and ocean environments support different organisms because ocean organisms are blocked by land from getting into lakes.

• The lake and ocean environments support different organisms because most freshwater organisms cannot live in saltwater.

• The lake and ocean environments support the same organisms because they are both water and are made up of the same elements.

Which ecosystem would be more likely to survive if a disease killed the grasses?

• The forest ecosystem, because most of the animals can eat other organisms

• The grassland ecosystem, because several predators compete for food

• The forest ecosystem, because it has three top predators

• The grassland ecosystem, because it has many herbivores