Environmental Science 124 Unit 2 Biodiversity Test

Front

What is a keystone species?

Back

A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Its presence or absence can significantly impact the structure and function of the ecosystem.

Front

Can you give an example of a keystone species?

Back

Sea otters are an example of a keystone species.

Front

Why are sea otters considered crucial to their ecosystem?

Back

Sea otters are crucial because they feed on sea urchins, which can overgraze kelp forests, leading to ecosystem degradation.

Front

What is species richness?

Back

Species richness refers to the number of different species present in a given area.

Front

How does high genetic diversity benefit a species?

Back

High genetic diversity helps a species cope with environmental changes by providing a greater range of traits that may be advantageous for survival.

Front

What is the species diversity index?

Back

The species diversity index is a quantitative measure that reflects how many different species are present in a dataset, as well as the abundance of each species.

Front

How do you calculate the species diversity index?

Back

The species diversity index can be calculated using the formula: D = 1 - (Σ(n/N)²), where n is the number of individuals of each species, and N is the total number of individuals of all species.

Front

What role do sea urchins play in the ecosystem?

Back

Sea urchins are herbivores that feed on kelp and other marine vegetation. When their population is unchecked, they can cause significant damage to kelp forests.

Front

What is the relationship between biodiversity and ecosystem stability?

Back

Higher biodiversity generally leads to greater ecosystem stability, as diverse ecosystems are better able to withstand environmental changes and disturbances.

Front

What factors can threaten biodiversity?

Back

Factors that threaten biodiversity include habitat destruction, pollution, climate change, overexploitation, and invasive species.