About this Study Set
This study set covers Statistics & Probability through
16 practice questions.
Challenging questions testing knowledge of statistical principles applied to animal populations, biodiversity, and environmental phenomena. Every question includes the correct answer so you can learn as you go — pick any format above to get started.
Questions & Answers
Browse all 16 questions from the
Statistical Ecology and Environmental Probability study set below.
Each question shows the correct answer — select a study format above to practice interactively.
1
What is the typical unit of measurement for biodiversity indices like the Shannon Diversity Index when applied to an insect community?
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A
Individuals per square meter
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B
Species richness (number of species)
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C
Bits per individual
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D
Nectar volume per flower
2
In a study of migratory bird flight patterns, if researchers observe a mean flight speed of 35 km/h with a standard deviation of 5 km/h, what is the probability, assuming a normal distribution, that a randomly selected bird flies at a speed between 30 km/h and 40 km/h?
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A
Approximately 0.34
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B
Approximately 0.68
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C
Approximately 0.95
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D
Approximately 0.997
3
The concept of 'ecological carrying capacity' is most closely related to which statistical model?
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A
Poisson distribution
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B
Logistic growth model
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C
Geometric distribution
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D
Exponential decay model
4
When analyzing the spatial distribution of a plant species, if the variance-to-mean ratio is significantly greater than 1, what type of spatial pattern is most likely indicated?
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A
Uniform (regular) distribution
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B
Random distribution
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C
Clumped (aggregated) distribution
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D
Even distribution
5
In a mark-recapture study to estimate the population size of a fish species, the Lincoln-Petersen estimator is used. If 150 fish are initially marked and released, and later 200 fish are captured, with 30 of them being marked, what is the estimated population size?
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A
750
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B
1000
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C
1500
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D
2000
6
The Kruskal-Wallis H test is a non-parametric statistical test used to compare medians across multiple independent groups. In ecology, it might be used to compare which of the following?
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A
The mean biomass of different forest types
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B
The distribution of nesting sites for different bird species
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C
The growth rates of a plant species under varying nutrient levels
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D
The species composition of benthic invertebrates in streams with different levels of pollution
7
What is the primary statistical assumption underlying the use of the chi-squared test for independence when analyzing the association between the presence of a specific pollinator and the abundance of a particular flower?
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A
The data are normally distributed.
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B
The expected frequencies in each cell are sufficiently large (e.g., > 5).
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C
The sample size is small.
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D
The two categorical variables are ordinal.
8
In environmental monitoring, if the detection limit of a pollutant is 0.01 µg/L, and a sample has a concentration below this value, it is often reported as 'non-detect'. Statistically, how should these 'non-detect' values be handled for calculating the mean concentration of the pollutant?
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A
They should be excluded from the calculation.
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B
They should be treated as zero.
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C
They should be replaced with the detection limit.
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D
They should be replaced with a value half the detection limit or imputed using statistical methods.
9
The concept of 'species accumulation curves' in biodiversity assessment is primarily used to estimate:
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A
The average lifespan of a species.
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B
The rate at which new species are discovered with increasing sampling effort.
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C
The total biomass of an ecosystem.
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D
The genetic diversity within a population.
10
When assessing the long-term trends of a threatened species population, what statistical concept is crucial for determining if observed changes are significant and not due to random fluctuations?
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A
Correlation coefficient
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B
Hypothesis testing
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C
Regression analysis
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D
Descriptive statistics
11
In a study of predator-prey dynamics, if the population of prey follows a geometric distribution, what does this imply about the probability of an individual prey surviving from one time interval to the next?
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A
It increases with population size.
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B
It is constant and independent of population size.
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C
It decreases as the population size increases.
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D
It is zero.
12
What type of statistical distribution is often used to model the number of rare environmental events, such as volcanic eruptions or extreme weather events, occurring in a fixed interval of time or space?
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A
Binomial distribution
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B
Normal distribution
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C
Poisson distribution
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D
Uniform distribution
13
When applying regression analysis to model the relationship between annual rainfall and forest fire frequency, what does a p-value of 0.01 for the rainfall coefficient typically indicate?
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A
The relationship is positive.
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B
There is a 1% chance the observed relationship is due to random chance.
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C
The correlation coefficient is 0.01.
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D
The model explains 99% of the variation in fire frequency.
14
In the context of conservation genetics, what statistical measure quantifies the loss of genetic variation in a small, isolated population over time due to random drift?
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A
Heritability
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B
Effective population size (Ne)
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C
Genetic drift
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D
Allele frequency
15
When analyzing the spatial clustering of trees in a forest, the 'nearest neighbor analysis' uses a statistic to compare the observed average distance between individuals to the expected distance under what type of distribution?
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A
Clumped distribution
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B
Uniform distribution
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C
Random distribution
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D
Normal distribution
16
If a researcher is testing the hypothesis that a new pollutant has no effect on the growth rate of algae, what is the null hypothesis (H₀) in statistical terms?
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A
The pollutant has a positive effect on algae growth.
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B
The pollutant has a negative effect on algae growth.
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C
The pollutant has no statistically significant effect on algae growth.
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D
The pollutant has a significant effect on algae growth.
