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AP®Environmental ScienceCollege BoardExam QuestionsUnit 3: PopulationsK-Selected & r-Selected Species

K-Selected & r-Selected Species (College Board AP® Environmental Science): Exam Questions

7 mins7 questions
11 mark

Which of the following describes a K-selected species?

  • Produces a large number of offspring with minimal parental care.

  • Exhibits rapid growth and early reproduction.

  • Invests significant parental care in a few offspring, leading to higher survival rates.

  • Thrives in unpredictable environments with frequent disturbances.

Choose your answer

21 mark

Which of the following best explains why K-selected species are more adversely affected by invasive species than r-selected species? 

  • K-selected species have higher reproductive rates than r-selected species, allowing them to quickly adapt to new competitors.

  • K-selected species have a lower reproductive rate than r-selected species, making them more vulnerable to rapid changes in their environment.

  • K-selected species have shorter lifespans than r-selected species, allowing them to recover quickly from disturbances.

  • K-selected species are typically generalists, enabling them to outcompete invasive species.

Choose your answer

31 mark

Which of the following is the correct method to calculate the population growth rate (r)?

  • r space equals space fraction numerator b i r t h s space plus space d e a t h s space plus space i m m i g r a t i o n space plus space e m i g r a t i o n over denominator i n i t i a l space p o p u l a t i o n end fraction

  • r space equals space fraction numerator b i r t h s space plus space i m m i g r a t i o n space minus space d e a t h s space plus space e m i g r a t i o n over denominator i n i t i a l space p o p u l a t i o n end fraction

  • r space equals space fraction numerator b i r t h s space minus space d e a t h s space x space i m m i g r a t i o n space x space e m i g r a t i o n over denominator i n i t i a l space p o p u l a t i o n end fraction

  • r space equals space fraction numerator b i r t h s space x space space d e a t h s space plus space i m m i g r a t i o n space minus space e m i g r a t i o n space over denominator i n i t i a l space p o p u l a t i o n end fraction

Choose your answer

41 mark

A population of rabbits starts with 200 individuals. Over the course of a year, 50 rabbits are born, 20 die, 10 immigrate, and 5 emigrate. What is the population growth rate (r)?

  • 0.175 (17.5%)

  • 0.125 (12.5%)

  • 0.075 (7.5%)

  • 0.225 (22.5%)

Choose your answer

51 mark

Which of the following describes a strategy used by K-selected species to ensure maximum survival of offspring?

  • Producing a large number of offspring with little parental care.

  • Reaching reproductive maturity quickly and reproducing frequently.

  • Having short lifespans and high juvenile mortality rates.

  • Providing extensive parental care and investing significant resources in a few offspring.

Choose your answer

61 mark

Which curve most likely represents an r-selected species that has just colonized a new environment?

Four graphs labelled A to D. Graph A shows population peaking and declining. B shows exponential growth. C shows logistic growth. D shows fluctuations around carrying capacity.

  • A

  • B

  • C

  • D

Choose your answer

71 mark

Which curve most likely represents a K-selected species that is well established in an area? 

Four graphs labelled A to D show population size over time: A peaks and declines, B grows exponentially, C stabilises after growth, D fluctuates after growth.

  • A

  • B

  • C

  • D

Choose your answer