IB Guiding Questions

According to the Nature of Science statement, what does sampling provide to scientists studying populations?

• An exact count of every individual in a habitat

• An estimate of a population

• A guaranteed error-free measurement

• A prediction of future population growth

What term describes the difference between an accurate count of a species and an estimated count from sampling?

• Confidence interval

• Sampling bias

• Sampling error

• Observer effect

Which action can reduce sampling error when estimating a population?

• Collecting more samples

• Using only one large sample

• Ignoring outliers in data

• Counting only adults

Which statement about sampling error is consistent with the Nature of Science note?

• Sampling error can be completely eliminated with enough samples

• Sampling error increases as more samples are collected

• Sampling error will always exist, though it can be reduced

• Sampling error only occurs in small populations

In the context of population studies, why is random sampling used?

• To ensure every individual is counted

• To obtain an unbiased estimate of population size

• To track the movement of tagged individuals

• To measure only abiotic factors

Which method is described as estimating the population size of motile species by capturing, marking, releasing, and later recapturing individuals?

• Quadrat sampling

• Transect sampling

• Capture-mark-release-recapture

• Aerial survey counts

In the Lincoln index formula, Population size estimate = M × (N / R). What does M represent?

• Number of individuals recaptured

• Number of individuals initially caught and marked

• Number of marked individuals recaptured

• Total population size

In the Lincoln index formula, what does N represent?

• Number of individuals initially caught and marked

• Number of individuals recaptured

• Number of marked individuals recaptured

• Net migration into the area

In the Lincoln index formula, what does R represent?

• Number of individuals recaptured

• Number of individuals initially marked

• Number of marked individuals recaptured

• Number of individuals released after second capture

An ecologist uses capture-mark-release-recapture. Which equation should be used to estimate population size?

• Population = M + N + R

• Population = (M × R) / N

• Population = M × (N / R)

• Population = (N − R) × M