Ecosystems UIL

If your local environment begins to turn into a desert, what will most likely happen to the organisms in the environment?

• A different variety of organisms will be supported rather than the ones that currently exist

• The populations of organisms currently existing in the environment will not be affected

• The new desert environment will be unable to support any populations of organisms

• The populations of organisms currently existing in the environment will increase

Complete this statement. The more diverse an ecosystem is --

• the fewer varieties of species are present

• the more threatened its populations are

• the more stable it is

• the more similar the species will be

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

• Extinction of a population from the ecosystem

• Removal of may populations of organisms

• decrease in biodiversity

• increase in biodiversity

Which ecosystem would most likely have the lowest biodiversity and population sizes 3 years later?

• After clearing land for a highway

• After a forest fire destroys the plant growth

• After a lava flow creates a new section of land

• After a river floods a cornfield

A flower bed is created at a school so flowers can be planted in the autumn. Over the summer, the flower bed is ignored. Which of the following should the students expect when they come back to school?

• Tree

• Weeds

• Nothing

• Shrubs

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

• They both support the same organisms, but will look different because of the type of water

• They support the same organisms because they are both water and are made up of the same elements

• They support different organisms because most freshwater organisms cannot live in saltwater

• They support different organisms because ocean organisms are blocked by land from getting into lakes

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

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

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

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

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

The role of a pioneer species in primary succession is to change a bare habitat into one that is suitable for other organisms. A species that is responsible for primary succession in an ecosystem is most likely able to --

• migrate during the winter

• survive any predator

• carry out photosynthesis

• live at high altitudes

What is the relationship between ecological succession and equilibrium in an ecosystem?

• There is no relationship

• Ecological succession prevents ecosystems from ever reaching equilibrium

• Ecological succession leads to equilibrium in an ecosystem

• They are the same thing

Students observe ecological succession of a field that has been left bare. Which of the following are the students likely to observe first?

• Formation of topsoil

• Growth of grasses and weeds

• Growth of shrubs and trees

• A mature grassland community