Population Ecology

Multiple Choice

Researchers have found that a local squirrel population fluctuates from year to year, increasing one year and decreasing the next. Which of the following factors would cause the squirrel population to grow?

• the birth rate is equal to the death rate

• emigration is greater than immigration

• the death rate is higher than the birth rate

• the birth rate is greater than the death rate

Multiple Choice

Two species of finches are in competition for the limited resources of an ecosystem. One species eats fruit and the second species eats seeds. If a third species of herbivore finches moves into the area, how will the ecosystem change?

• Resources will be more abundant.

• Water will become more available.

• The climate of the ecosystem will change.

• Fruit and seed resources will become less abundant.

Multiple Choice

A population of flat-tailed horned lizards was found in a geographically isolated area. In 2002, the size of the population was about 25,500. In 2004, the size of the population was about 32,800. Which of the following statements explains the change in the size of the lizard population from 2002 to 2004?

•  

  The birth rate was greater than the death rate.

• The emigration rate was greater than the birth rate.

• The death rate was greater than the immigration rate.

• The emigration rate was greater than the immigration rate.

Multiple Choice

Which of the following graphs shows a population of organisms with a carrying capacity?

Multiple Choice

Which of the following is an exponential graph?

Multiple Choice

Define "carrying capacity"

• any factors in an environment that are limited

• when population increases slowly at first then grow at an accelerated rate

• minimum number of individuals of a species that an environment can support

• maximum number of individuals of a species that an environment can support

Multiple Choice

Define "limiting factor"

• anything that constrains a population's size and slows or stops it from growing

• when population increases slowly at first then grow at an accelerated rate

• minimum number of individuals of a species that an environment can support

• maximum number of individuals of a species that an environment can support

Multiple Choice

Which of the following is NOT a density dependent limiting factor?

• competition

• parasitism

• disease

• natural disaster

Multiple Choice

Cattle egrets forage (feed) in fields among cattle. The egret gets easy access to flying insects stirred up by the cattle, and the cattle don't care if they are there or not.

• mutualism
• commensalism
• competition
• parasitism

Multiple Choice

What type of symbiosis?  Hummingbirds feed on nectar from flowers.  The flowers are pollinated by hummingbirds as they move from flower to flower.

• commensalism
• mutualism
• parasitism
• predation

Multiple Choice

Which symbols best describe parasitism?

• +,+
• +,-
• +,0
• -,0

Multiple Choice

Different species are most likely to compete for resources in an ecosystem if both species attempt to –

• occupy the same niche.
• successfully reproduce.
• live in different habitats.         
• find different food sources.   

​Questions?