12 Biology - Ecology

Certain species are dependent upon one another and so may be classified or grouped together, as conservation strategies must take management of both of them into account.

Identify the species interaction being described.

•  predation

• competition

• symbiosis

• disease

Identify a method by which scientists can minimise bias in their randomised sampling of an ecosystem.

• using transects

• using quadrats

• using random number generators

• recording the location of sample sites so that further surveys can be carried out

Recall the definition of ‘carrying capacity’.

• the minimum size of a population that can be supported indefinitely on the available resources and services of an ecosystem

• the maximum size of a population that can be supported indefinitely on the available resources and services of an ecosystem

• the number of species that can be supported indefinitely on the available resources and services of an ecosystem

• the size of a population that will allow the resources and services of an ecosystem to grow

A biologist captures 24 spotted-tailed quoll (Dasyurus maculates), tags them, and releases them unharmed. A week later, she captures 18 quoll, including 14 with tags.

N=M x n / m 

where:

M = number of individuals caught, marked and released initially

n = number of individuals caught on second sampling

m = number of individuals recaptured that were marked

Identify the population size.

• 28

• 29

• 30

• 31

Which one of the following is a density-independent factor?

• Crowding

• Predation

• Natural Disasters

• Competition for resources

Which one of the following is a density-dependent factor?

• Predation

• Salinity

• Sunlight

• Temperature

Identify the kind of population growth shown in the graph.

• Exponential growth J - Curve

• exponential growth S-curve

• logistic growth J-curve

• logistic growth S-curve

Identify the kind of population growth shown in the graph.

• exponential growth J-curve

• exponential growth S-curve

• logistic growth J-curve

• logistic growth S-curve

Calculate SDI

• 0.82

• 0.13

• 0.86

• 0.91

Define 'Tolerance range'