Question

the death by bubonic plague of about one - third of europes population during the fourteenth century is a good example of
abiotic factors limiting population size.
density dependent effect
density independent effect

the bullfrog lays hundreds of eggs that are fertilized. only a small percentage of these eggs will reach reproductive age. this is an example of
type i survivorship curve
type ii survivorship curve
type iii survivorship curve

an ecologist hypothesizes that predation by a particular owl species is the major factor controlling the population of a particular rabbit species. if this is the case, which of the following population effects could be expected in this rabbit - owl pair?
a fall in the owl population should cause a fall in the rabbit population.
a fall in the rabbit population should cause an increase in the owl population.
an increase in the owl population should cause a fall in the rabbit population

Explanation:

• First Question: Density - dependent factors are influenced by population size. The bubonic plague (a disease) spreads more easily in a densely populated area (more people to infect), so it is a density - dependent effect.
• Second Question: Type III survivorship curves are characterized by high mortality in the early stages of life. Bullfrog eggs have a high mortality rate (only a small percentage reach reproductive age), which is typical of Type III.
• Third Question: If owls (predators) increase, they will consume more rabbits (prey), so an increase in the owl population should cause a fall in the rabbit population.

Answer:

• First Question: density - dependent effect
• Second Question: Type III survivorship curve
• Third Question: An increase in the owl population should cause a fall in the rabbit population.