Population Ecology

plants --> rabbits --> foxes --> hawks

Which of these is most likely to occur to the populations immediately after a wildfire burns the environment.

• hawks and foxes increase

• hawks decrease; foxes increase

• plants decrease; rabbits increase

• plants and rabbits decrease

In the desert, cactus wrens often build nests in cholla cacti to avoid predators; this does not hurt the cacti. What type of relationship is this?

• competition

• commensalism

• mutualism

• parasitism

This graph best represents which ecological concept?

• exponential growth

• predator-prey relationship

• carrying capacity

• flow of energy through food web

Over a period of 200 years, a mountain pond transformed into a meadow. Which of these explains why new communities replace the old communities?

• the original species all became extinct

• species in the old community died from old age

• diseases that killed the older organisms disappeared

• abiotic characteristics of the habitat changed

The graph shows birth and death rates for a population. From 1900 to 2000, the population has

• increased

• decreased

• remained constant

• increased until 1930 then decreased

Which of these types of organisms would most likely have the largest population in a pond ecosystem?

• algae

• fish

• frogs

• snakes

The diagram shows a lake ecosystem divided into 3 life zones. Why is there a greater diversity of life found in zone 1?

• it has the greatest rate of evaporation

• it is always warmer than the other zones

• the other two zones don't have dissolved oxygen

• it receives the most sunlight

A scientist measured flower heights at many different elevations on a mountain. Which statement best describes the pattern of growth for flowers during the experiment?

• flower height is unaffected by elevation

• flower height decreases with decreasing elevation

• flowers grow taller around elevations of 3000 meters

• flower height increases with increasing elevation

The graph shows rabbit population over a 7 year period. What is the approximate carrying capacity for rabbits?

• 200

• 400

• 500

• 600

What do the arrows in the diagram represent?

• flow of water

• flow of sunlight

• flow of energy

• flow of bacteria