In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%?

In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%? 

A) 2,700,000
B) 5,500,000
C) 303,000,000
D) 304,000,000
E) 2,710,800,000





Answer: D

Which of the following is the equation for zero population growth (ZPG)?

Which of the following is the equation for zero population growth (ZPG)? 

A) R = b - m
B) dN/dt = rN
C) dN/dt =rmax N (K -N)/K
D) dN/dt =rmax N
E) dN/dt = 1.0N







Answer: A

Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.)

Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.) 

A) 6
B) 18
C) 128
D) 512
E) 1,024





Answer: D

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year.

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year. 

A) 120 individuals added
B) 40 individuals added
C) 20 individuals added
D) 400 individuals added
E) 20 individuals lost





Answer: B

Which of the following is the most important assumption for the capture-recapture method to estimate the size of wildlife populations?

Which of the following is the most important assumption for the capture-recapture method to estimate the size of wildlife populations? 

A) All females in the population have the same litter size.
B) More individuals emigrate from, as opposed to immigrate into, a population.
C) Over 50% of the marked individuals need to be trapped during the recapture phase.
D) There is a 50:50 ratio of males to females in the population before and after trapping and recapture.
E) Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.




Answer: E

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve?

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve? 

A) Many invertebrates mate and produce offspring on multiyear cycles.
B) Within a species of invertebrates, younger individuals have a higher survivorship than older individuals.
C) Many invertebrates molt in order to grow, and they are vulnerable to predation during their "soft shell" stage.
D) Many invertebrate species have population cycles that go up and down according to the frequency of sunspots.
E) The number of fertilized eggs that mature to become females in many species of invertebrates is based on ambient temperature.




Answer: C

Which of the following best defines a cohort?

Which of the following best defines a cohort? 

A) a group of individuals that inhabits a small isolated region within the range for the species
B) all of the individuals that are annually added to a population by birth and immigration
C) the reproductive males and females within the population
D) a group of the individuals from the same age group, from birth until they are all dead
E) the number of individuals that annually die or emigrate out of a population





Answer: D