Unit 3: Classifying Ecosystems.3

What is the purpose of stratified sampling?

• To avoid sampling biotic components

• To estimate population means, density, and distribution

• To only measure abiotic components

• To ignore environmental gradients

What is a stratum in the context of stratified sampling?

• An individual area sampled within the overall habitat

• A type of quadrat

• A systematic sample

• A random sample

Which of the following is NOT a purpose of stratified sampling?

• Estimating population density

• Ignoring environmental gradients

• Considering zonation

• Considering stratification

What is important when selecting a site for sampling?

• Recording the location without marking the site

• Only marking the site without recording the location

• Clearly marking out the site and accurately recording the location

• Ignoring the location

What is a quadrat?

• A type of stratum

• A method to ignore biotic components

• A sampling line

• An area where you survey the organisms present

Which of the following is NOT a consideration when using quadrats?

• Size

• Number used

• Ignoring the density

• How they are placed

What is a transect used for?

• To measure the width of rivers

• To investigate change over distance in an ecosystem

• To ignore environmental gradients

• To measure the height of trees

What does random, unbiased sampling provide?

• The least accurate data

• The most accurate data

• No data at all

• Only qualitative data

What is the aim of sampling?

• To only sample abiotic components

• To ignore the population

• To select a sample which is not representative of the population

• To select a sample which is representative of the population

What should be considered when using quadrats?

• Only frequency

• Only density

• Only percentage cover

• Density, frequency, and percentage cover