A Keystone Species Is One

question 24

Multiple Choice

A keystone species is one

• A) that makes up a very large proportion of total community biomass.
• B) that feeds on a very large fraction of all available prey species.
• C) that is fed on by a very large fraction of all predators in its community.
• D) whose feeding activities have a disproportionate effect on the structure of its community.
• E) that occupies the lowest level (the base) of the food web.

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Definitions:

Heritability

A measure of how much of the variation in a trait within a population is due to genetic differences among individuals in that population.

Twin Studies

Studies of the heritability of a disorder by comparing concordance rates between monozygotic and dizygotic twins.

Identical Twins

Twins resulting from the splitting of a single fertilized egg, sharing the same genetic material and thus being genetically identical.

Genes

Units of heredity made up of DNA that act as instructions to make molecules called proteins, affecting how organisms inherit traits from their parents.