Biology Unit 2 Ecology IHS Skavaril

Why is ecology important

it helps us understand how life on Earth is connected and how we depend on the environment for things like clean air, water, and food; humans + Earth = healthy and clean

Pyramid of Biomass

Shows how matter cycles in a ecosystem; measures mass of biotic factors.

Explain the carbon cycle

1. Atmosphere to biotic factors: photosynthesis

2. Atmosphere to water: dissolve

3. Water to rock: sedimentation

4. Water to atmosphere: diffusion

5. Biotic factors to atmosphere: decomposition/respiration

6. Biotic factors to fossil fuels: fossilize

7. Fossil fuels to atmosphere: combustion

Explain the nitrogen cycle

1. Atmosphere to soil: nitrification

2. Ammonia to nitrate in soil: nitrification

3. Soil to water: leeching

4. Soil to atmosphere: denitrification

5. Organism that does the work of transforming nitrogen: bacteria

Explain the hydrological cycle

1. Atmosphere to surface: precipitation

2. Surface to atmosphere: evaporation

3. In the atmosphere: condensation

4. Surface to body of water: runoff

5. Surface to ground water: seepage

6. Biotic factors to atmosphere: transpiration

How is carrying capacity determined

By limiting factors (food, water, shelter, space

What is exponential growth (aka J curve)

Fast growth; population is rapidly increasing

What is logistic growth (aka S curve)

After exponential growth, rate can slow and stop

What is population crash

Exceed in carrying capacity; population plummets down

What are density-dependent factors

Factors more likely to change carrying capacity as the population increases (e.g. predation, competition, disease)

What are density-independent factors

Factors likely to change carrying capacity no matter what the population is (e.g. weather, humans, natural disasters)

What causes population to increase

Birth and immigration

What causes population to decrease

Death and emmigration

What is a food chain

Shows energy flowing in one direction

What is a food web

Shows energy flowing in all directions

Which way does energy flow

In one direction through an ecosystem, away from the sun

Where does energy usually start

Energy usually starts with the sun, which is captured by autotrophs, and then consumed by heterotrophs

What is a system

Interconnected parts that functions as a whole

What is systems thinking

Everything is connected in systems; if one thing works differently, so will the system. One part changes, everything does

What is the atmosphere

A mixture of gases that surround Earth

What is the geosphere

Rocky, solid part of the earth. minerals, mountains, interior of Earth

What is the hydrosphere

All the water on earth

What is the biosphere

The part of Earth where life exists; all living things

What is random population dispersion

Put in random places

What is uniform population dispersion

Spread out evenly

What is clumped population dispersion

One big group

What is the importance of keystone species in a ecosystem?

Keystone species protects producers → increase in producer population → increase in consumers → more interactions → more biodiversity → more resilient → more stable

Autotroph/Producer

An organism that gets energy via photosynthesis and chemosynthesis (abiotic factors)

Herbivore

An organism that gets energy by eating producers

Decomposer

An organism that gets energy by breaking down dead organic matter

Biodiversity

The variety of life on Earth; provides essential services like clean air and water, supports food security and medicine, and makes ecosystems more resilient to change. Increase interactions and stabilize an ecosystem

Carnivore

An organism that gets energy by only eating animals

Commensalism

One organism benefits and the other organism is not impacted/affected

Biome

All the ecosystems controlled by one climate

Community

All the biotic factors in one ecosystem

Ecosystem

All abiotic and biotic factors in one area

Mutualism

Both organisms benefit

Resilience

The ability of an ecosystem to recover and adapt after being disturbed, such as from a natural disaster or human activity

Niche

The role an organism plays within its ecosystem

Habitat

The place where a particular animal or plant (or species of animal or plant) lives

Interspecific competition

Organisms from different species competing for the same resources

Intraspecific competition

Organisms from same species competing for the same resources

Primary consumer

An organism that gets energy by consuming producers

Secondary consumer

An organism that gains energy by eating primary consumers

Tertiary consumer

An organism that gains energy by eating secondary consumers

Immigration

The movement of individuals into a population's area from another population or region

Emigration

The act of a population of organisms leaving their habitat to move to another place

Nitrogen fixation

Process where atmospheric nitrogen, which most organisms cannot use, is converted to a useable nitrogen compound (e.g. ammonia)

Omnivore

An organism that gets energy by eating both plants and animals

Chemosynthesis

Capturing energy from chemicals

Detritivore

An organism that gets energy by eating dead organic matter (smaller matter like feces, dead leaves)

Scavenger

An organism that gets energy by eating dead organic matter (large pieces like dead animals)

Trophic level

A level of energy (producers, primary consumers, etc.) 90% of energy is lost in each level

Nitrification

Two-step process where bacteria in soil and water convert ammonia into nitrites and then into nitrates

Denitrification

Microbial process where bacteria convert nitrates and nitrites into nitrogen gas, which is released into the atmosphere

Population

All members of one species in one community

Population density

Number of individuals / area (unit²)

Parasitism

One organism benefits and one organism is negatively impacted

Predation

One organism hunts and kills another organism

Weather

Day to day conditions of Earth's atmosphere

Climate

Long term patterns of temperature and precipitation over many years

Energy pyramid

Shows how energy flows in a ecosystem

Pyramids of Numbers

Shows # of organisms available in a ecosystem/in each trophic level

Individual

One of a population

Photosynthesis

Capturing energy from sunlight

What makes biomes different from each other

Climate

Which is one way that the movement of matter through an ecosystem is different from the transfer of energy

Only the movement of matter occurs in an unending cycle; matter cycles, energy flows