Ecology

Ecology Unit for Semester 1, Quarter 1. Taken directly from the notes.

Ecology

The study of the interaction of organisms and the living and non-living components of the environment

Interdependence

The survival of organisms depends on the interactions between the living and non-living aspects of the environment

Ecological Model

Represents and describes the components of an ecological system

Biosphere

The broadest, most inclusive level of organization

In the biosphere

Where are all organisms found?

Ecosystems

Include all of the organisms and nonliving environments found in a particular area

Community

All of the interacting organisms living in an area

Population

Includes all the members of a species that live in one place at one time

Organism

The simplest level of organization

Biosphere, ecosystem, community, population, and organism

Name the 5 levels of ecological organization in order from largest to smallest.

Habitat

The place where an organism lives

Biotic factors

The living components of an environment

Abiotic factors

The nonliving components (physical and chemical characteristics) of the ecosystem

Tolerance curve

A graph that shows the performance of an organism versus an environmental variable

Acclimate

To adjust

Conformers

Organisms that do not regulate their internal conditions, they change as their environment changes

Regulators

Organisms that use energy to control some of their internal conditions within a wider variety of environmental conditions

Dormancy

A state of reduced activity

Migrate

To move to a better habitat

Niche

A specific role or way of life with an environment

Generalists

Organisms that can tolerate a wide range of environmental conditions

Specialists

Organisms that have narrow niches

Autotroph (Producers)

An organism that makes its own food by capturing energy to make organic molecules

Chemotrophs

Carry out a process called chemosynthesis

Chemosynthesis

Used energy stored in inorganic molecules to produce carbohydrates

Gross Primary Productivity

The rate at which producers in an ecosystem capture energy of sunlight by making organic compounds

Biomass

The amount of organic material that is produced in an ecosystem

Only other organisms

Can access energy that is stored as biomass

Net Primary Productivity

The rate at which biomass accumulates

Consumers

Must get energy by consuming organic molecules

Herbivores

Organisms that eat producers; Predators that eat plants

Carnivores

Organisms that eat other consumers; Predators that eat animals

Omnivores

Organisms that eat both producers and consumers

Detritivores (Decomposers)

Consumers that feed on the “garbage” of the ecosystem

Energy is transferred

What happens when organisms eat each other?

From the producers to the consumers

How does energy in an ecosystem flow?

Food chain

A single pathway of feeding relationships among organisms in an ecosystem that results in energy transfer

Food web

Many food chains interlinked to look like a web

On average, only about 10% of the energy from one trophic level will make it to the next level

What is the 10% rule?

Organisms on the lowest trophic level (Producers)

What organisms are most abundant in an ecosystem?

Yes, because they carry less energy therefore they support less individuals

Do higher trophic levels contain less individuals? Explain.

Predation

Predator eats prey

Heterotrophs

Organisms who eat for energy; Either predators, parasites, or both

Running away, hiding, resembling inedible objects, deceptive coloring, and chemical defenses

Give 5 examples of how animals avoid predators.

Mimicry

One species closely resembles another species

Batesian mimicry

A harmless king snake is a mimic of the venomous coral snake (Example)

Because they cannot run away

Why are plants especially vulnerable to predators?

Thorns, spines, sticky hairs, and thick leaves

Give 4 examples of physical defenses plants have developed.

Interspecific competition

a type of interaction in which two or more species are competing for the same limited resource

Competitive exclusion

When one species is eliminated from a community because of competition for the same limited resource

Symbiosis

A close long-term relationship between two organisms

Parasitism, mutualism, and commensalism

Name the 3 types of symbiotic relationships.

Parasitism

A host is harmed by a parasite (+,-)

Mutualism

Two species derive some benefit from one another (+,+)

Pollination of a plant by a bee

Give an example of a mutualistc relationship.

Tapeworms, fleas, and ticks latching onto a host

Give an example of a parasitic relationship.

Commensalism

One species benefits and the other species is unaffected (+,=)

Scavengers eating the leftovers that another animal left behind

Give an example of a commensalistic relationship.

Ecological succession

The gradual, sequential regrowth of a community of species in an area

Primary and secondary

What are the two types of succession?

Primary succession

Occurs in an area that has never previously supported life

Secondary succession

The sequential replacement of species that follows a disruption of an existing community.

Primary: An island formed by a volcano

Secondary: Fire or human activity

Give an example of both primary and secondary succession

Pioneer species

Organisms that predominate early succession.

Climax community

When a community proceeds through the predictable series of stages until it reaches a stable end point

Evaporation, transpiration, and precipitation.

What are three important processes in the water cycle?

Evaporation

Water returns to its original gaseous form as water vapor, and is added back into the atmosphere

Transpiration

The process by which water evaporates from the leaves of plants in terrestrial ecosystems

Precipitation

Water returns from the atmosphere to the Earth

To make protein and nucleic acids

Why do organisms need nitrogen?

Nitrogen cycle

The complex pathway that nitrogen follows in an ecosystem

Nitrogen fixation

Nitrogen must be converted to a nitrate in order to be usable for plants

Nitrogen fixing bacteria, but some may even use lightning

What do most organisms rely on to transform atmospheric nitrogen gas into a usable form?

Ammonification

The process of converting ammonia to ammonium from urine, feces, and decaying bodies

Nitrification

Occurs when soil bacteria convert nitrites to nitrates

Denitrification

Returns nitrogen to the atmosphere when anaerobic bacteria break down nitrates and release them back into the atmosphere

Phosphorus

An essential material for animals; Needed for bones, teeth, and DNA and RNA

Plants get the phosphorus they need from soil and water, whereas animals get it by eating plants

How do plants and animals differ in the way they get phosphorus?

Through their roots

How do plants absorb phospates?

Phosphate PO₄³⁻

When rocks erode small amounts of phosphorus, it dissolves as _____ in the soil/water