Chapter 4 Test

What is adaptation (adaptive trait)?

Any heritable trait that improves the ability of an individual organism to survive and to reproduce at a higher rate.

Define Biodiversity (biological diversity) and list and describe its four major components.

Biodiversity is the variety of earth's species, the genetics they contain, where they live, and the processes (Like energy flow and nutrient cycling) the sustain all life. The four major compenents are genetic, functional, ecological, and species diversity

Define and give three examples of biomes.

Biomes are large regions with distinct climates and certain species that have adadpted to living in them. Forests, deserts, and grasslands.

Describe how geological processes can affect natural selection.

Geological processes have the potential to isolate species and because of natural selection, these species were able to adapt and overcome to their new environment

What is a mutation and what role do mutations play in evolution by natural selection?

Mutations are the changes in the DNA molecules of a gene in any cell that can be inherited by offspring. Mutations are considered a favorably trait, which means it's passed down to assist that species survive natural selection.

Define and distinguish among native, nonnative, indicator and keystone species and give an example of each.

Native species are species that normally live and thrive in a particular ecosystem, nonative species are ones that migrate or are introduced to an ecosystem, indicators are species that provide early warnings or damage to a community or ecosystem, and keystone species are species whose roles have a large effect on the types and abundance of other species in an ecosystem.

What are two limits on evolution by natural selection?

One limit is evolution can only happen if the trait thats being improved is already in that species or has to come from mutation. A second limit is the ability to adapt quickly, which bigger species can't do.

Define species diversity and distinguish between species richness and species evenness.

Species diversity is the number or variety of species an ecosystem contains. Species richness is the number of different species in a given area, while species evenness is the measure of the relative abundance of individuals of each species present. The more even the numbers of individuals of eahc species, the higher the species evenness.

What is an endemic species and why can such a species be vulnerable to extinction?

Speices that are only found in one area. They're vulnerable to extinction because since they usually have a highly important role in the ecosystem they're in, they are less likely to migrate and/or adapt to a rapidly changing habitat.

Explain why species-rich ecosystems tend to be productive and sustainable.

The more diverse an ecosystem is the more productive it will be along with more stable/sustainable. A place with different species provides more food options and better ways to respond to stressful environmental changes. The species all go their own paths, mant dont rely on others.

Distinguish between background extinction rate and mass extinction.

background extinctionr rate is the low rate at which species become extinct, while mass extinction is a fast period of time that a species start dying out and going extinct.

Distinguish between geographic isolation and reproductive isolation and explain how they can lead to the formation of new species.

geographic isolation is the seperation of species through physical or migration means, while reporductive isolation is when mutation and change by natural selection both work independitly in a species gene pool or geographical isolated species and if it happens for long enough, the now spilt species are so genetically different that they cant reproduce. This can lead to new species because once the genetics change enough and cant reproduc with the original populaton, they're considered a new species.