Question

independent practice

1. 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?

a. the birth rate is equal to the death rate
b. emigration is greater than immigration
c. the death rate is higher than the birth rate
d. the birth rate is greater than the death rate

1. populations do not continue to grow to an unlimited size. their environment, including food and other natural resources, limits their size eventually. this limit is called the

a. differential population.
b. carrying capacity.
c. prey maximum.
d. predator limit

1. 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 finches that eats seeds and fruits move into the area, how will the ecosystem change?

a. resources will be more abundant.
b. water will be more available.
c. the climate of the ecosystem will change.
d. fruit and seed resources will become less abundant.

1. over a period of time, the location of the dashed line would move from location b to location c on the graph if the birth rate of the rabbit population was equal to the death rate of the rabbit population.

a. there was a decrease in the number of rabbit predators and an increase in the availability of plants.
b. there was a decrease in the availability of food, minerals, water, and shelter.
c. the entire rabbit population migrated to a new ecosystem containing more autotrophs

1. the iberian lynx is a large cat that is native to spain and portugal. over the last few decades, the lynxes main food source, rabbits, have contracted a disease called myxomatosis. myxomatosis only causes death in rabbits. how would this most likely affect the population of lynx?

a. the lynx population would remain the same because they would adapt to eating other food.
b. the lynx population would increase because they would produce more offspring to make up the difference.
c. the lynx population would decrease because they would also contract the disease.
d. the lynx population would decrease since they wont have access to as much food

1. scientists that study the effects of global warming predict that a change in earths average temperature of even a few degrees will have dramatic effects. one consequence of global warming is the melting of the polar ice caps, which will in turn affect polar bears that use sea ice as a platform for hunting seals. what will most likely happen to the population of polar bears as a result of global warming?

a. it will increase as polar bears adapt to other habitats.
b. it will increase because polar bears will have fewer predators.
c. it will decrease as the habitat suitable for polar bears decreases.
d. it will decrease because polar bears will become easier to hunt.

Explanation:

1. Population growth occurs when the birth rate is greater than the death rate.
2. The maximum number of individuals an environment can support is called the carrying capacity.
3. With a new species competing for the same resources, fruit and seed resources will become less abundant.
4. If birth rate equals death rate, a decrease in predators and increase in plant availability would cause the population to move to a higher - level location on the graph.
5. Since rabbits are the main food source of the lynx and the rabbit population is affected by disease, the lynx population will decrease due to less food access.
6. As the habitat suitable for polar bears (sea - ice platform for hunting) decreases due to global warming, the polar bear population will decrease.

Answer:

1. D. the birth rate is greater than the death rate
2. B. carrying capacity
3. D. Fruit and seed resources will become less abundant.
4. A. there was a decrease in the number of rabbit predators and an increase in the availability of plants.
5. D. The lynx population would decrease since they won't have access to as much food
6. C. It will decrease as the habitat suitable for polar bears decreases.