AP Environmental Science - Unit 2: The Living World: Biodiversity

Flashcards covering key concepts from the AP Environmental Science lecture notes on biodiversity, biogeochemical cycles, ecosystems, and evolution.

What are the five biogeochemical cycles?

Carbon, nitrogen, phosphorus, sulfur, and water cycles.

What components do biogeochemical cycles encompass?

Living (Bio), geological (Geo), and chemical components.

What are reservoirs in biogeochemical cycles?

Places where large quantities of nutrients are stored for a long amount of time.

What are exchange pools in biogeochemical cycles?

Sites where nutrients stay for a short amount of time.

What is residency time in biogeochemical cycles?

The amount of time a nutrient spends in a reservoir or exchange pool.

What are the two main sources of energy in a biogeochemical cycle?

The sun and the heat from the mantle and core.

What is sublimation?

Water goes from solid to gas without achieving liquid form.

What is infiltration?

Movement of water from the land to the underground.

What happens during respiration in the carbon cycle?

Where animals and plants inhale oxygen and release carbon dioxide.

What happens during photosynthesis in the carbon cycle?

Plants take in carbon dioxide, water, and energy from the sun to produce carbohydrates and oxygen.

How can carbon be released into the atmosphere?

Through combustion (the burning of fossil fuels) and volcanic eruption.

What are the important reservoirs in the carbon cycle?

The world’s oceans and rocks.

What is nitrogen fixation and why is it important?

The process where nitrogen is converted into ammonia or nitrates by bacteria (like Rhizobium) so plants can use it.

What is nitrification?

Soil bacteria convert ammonia into nitrites, which are then converted into nitrates. Plants can then use them.

What is assimilation?

Plants absorb ammonium, ammonia ions, and nitrate ions into their roots, and then heterotrophs eat the plants and absorb nitrogen through proteins and nucleic acid.

What is ammonification?

The process where bacteria convert dead organisms and other waste into ammonia ions, which are reused or released into the atmosphere.

What is denitrification?

Special anaerobic bacteria converts the ammonia back into nitrites and nitrates and then into nitrogen gas.

In what forms is phosphorus found?

Soil, rock, and sediments.

How is phosphorus typically released?

Through chemical weathering.

In what form is phosphorus absorbed?

In the form of phosphate.

Where does phosphorus NOT exist?

Atmosphere.

What are biomes?

Land environments split into further categories based on climate, geology, soils, topography, hydrology, and vegetation.

What are ecozones?

Small regions within ecosystems that share similar features.

What are ecotones?

The transitional area where two ecosystems meet.

What is the Law of Tolerance?

The degree at which a habitat can tolerate significant changes to the environment.

What is the Law of Minimum?

Organisms will continue to live, consuming available materials until the supply is exhausted.

How does rainfall and soil type affect deciduous forests?

They have a temperate and tropical climate that can have 75-250 cm of rainfall. The soil is also rich and contains high organic content.

How does rainfall and soil type affect the tropical rainforest?

They can have a 200-400 cm rainfall with poor soil quality.

How does rainfall and soil type affect grassland biomes?

The rainfall amount can be 10-60 cm with rich soil.

How does rainfall and soil type affect coniferous forests/ taigas?

The rainfall amount can be 20-60 cm mainly in summer, also the soil is acidic due to vegetation.

How does rainfall and soil type affect the tundra biome?

The rainfall amount is less than 25 cm with the soil being permafrost.

How does rainfall and soil affect the chaparral biome?

The rainfall amount is 50-75 cm with infertile and shallow soil.

How does rainfall and soil type affect desert biomes?

The rainfall amount is less than 25 cm, with the soil having a coarse texture soil.

What is biodiversity?

When an area has a variety of organisms in its region, and also the genetic diversity within the region's species.

What are autotrophs?

Organisms that produce their own organic compounds from inorganic chemicals.

What are heterotrophs?

Organisms that obtain energy by consuming other organisms or products created by them.

What is a trophic level?

Each level on a food chain.

What is the Ten Percent Rule?

Only 10% of energy is transferred to the next trophic level, and the rest is lost as heat.

What is Bioaccumulation?

When substances like chemical toxins accumulate in the tissues of living organisms.

What is Biomagnification?

When the increasing concentration of toxic molecules are at high trophic levels.

What are food webs?

Extensive food chains that are used to show feeding relationships in ecosystems more accurately.

What are producers?

Organisms, typically plants and algae, that take inorganic materials and solar energy and create carbohydrates.

What are primary consumers?

Herbivores that consume only producers.

What are secondary consumers?

Organisms that consume primary consumers.

What are tertiary consumers?

Organisms that consume secondary consumers.

What are detritivores?

Organisms that get energy from consuming non-living organic matter.

What are decomposers?

Organisms that consume dead plant and animal material; they return nutrients to the soil.

What are saprotrophs?

Organisms that use enzymes to break down dead matter and absorb nutrients.

What is evolution?

The change in a species' genetic makeup over time, which causes biodiversity.

What is speciation?

How new species are created.

What determines Evolutionary fitness?

Individual organisms that are better suited for their environment will live longer and reproduce.

What is Natural Selection?

Habitats enable certain organisms to live and reproduce and others to die.

What is a gene pool?

Genetic makeup of a population.

What is genetic drift?

Another way of evolution where the accumulation of changes is often in the alleles, a version of genes, and occurs overtime due to random chance.

What is biological extinction?

NO species left living on planet

What is ecological extinction?

Very little amount of species left to the point where they cannot perform their ecological niches

What is commercial or Economic extinction?

Few survivors left, but the expenses to save them aren’t deemed worth spending.

What is species competition?

when two animals of the same or different species compete for a resource. There are two types: Interspecific, for different species and Intraspecific for the same species.

What is Competitive Exclusion?

when two species compete and the better adapted species wins.

What is Guase’s Principle?

no two species can share a niche.

What is resource partitioning?

when different species use slightly different parts of a habitat.

What are Symbiotic Relationships?

Relations between two or more species that are often prolonged and have at least one benefiting party. Consisting of commensalism, mutualism, and parasitism.

What is Predation?

relationship where one species feeds on another.

What are keystone species?

species whose presence contribute to an ecosystem's diversity, and the absence of that presence would make many other species go extinct.

What are indicator species?

help evaluate the health of an ecosystem.

What are indigenous species?

naturally occurring species in a habitat.

What are introduced or invasive species?

species brought to a habitat where they did not originally live.

What are pioneer species?

found in the first stages of ecological succession, they are likened to many habitats and can quickly adapt.

What is Ecological succession?

the changing and growing of an ecosystem.

What are primary and secondary successions?

primary happens in a virtually lifeless area, while secondary happens where an existing community has been removed or cleared.

What is habitat fragmentation?

when a habitat is reduced or isolated

What is The Theory of Island Biogeography?

the number of species found in an undisturbed area is determined by immigration and extinction.