Bio

What is ecology?

The study of how organisms interact with each other and their environment.

What is the biosphere?

All life on Earth and every place where life exists.

What is a population?

A group of individuals of the same species living in the same area.

What is a community?

Different populations living together in one area.

What is an ecosystem?

All living things and their physical environment interacting in one area.

What is a biome?

A group of ecosystems with similar climates and organisms.

What is a producer (autotroph)?

An organism that makes its own food using sunlight or chemicals.

What is photosynthesis?

The process that converts sunlight, carbon dioxide, and water into energy and oxygen.

What is chemosynthesis?

Using chemical energy from inorganic compounds to make food.

Why must an autotroph start every food chain?

Because it produces the energy that all other organisms depend on.

What are consumers (heterotrophs)?

Organisms that obtain energy by eating other organisms.

List six types of consumers.

Carnivores, herbivores, scavengers, omnivores, decomposers, detritivores.

What is the 10% rule?

Only about 10% of the energy at one trophic level is passed to the next.

Why can’t energy be recycled?

It’s lost as heat at each step of the food chain.

What does 'energy flows, matter cycles' mean?

Energy moves one way through an ecosystem; matter is reused and recycled.

What are the three ecological pyramids?

Energy, biomass, and numbers.

What drives all three pyramids?

The loss of energy between trophic levels.

Define niche.

A species’ role in its environment—how it gets food, shelter, and survives.

Give five parts of an oak tree’s niche.

Provides shade, produces oxygen, offers shelter, absorbs CO₂, stabilizes soil.

What is symbiosis?

A close relationship between two species living together.

Name and describe the three types of symbiosis.

Mutualism (both benefit), commensalism (one benefits, other unaffected), parasitism (one benefits, other harmed).

Give one example of each symbiotic relationship.

Bees/flowers (mutualism), barnacles/whales (commensalism), fleas/dogs (parasitism).

What is a keystone species?

A species that has a major effect on the structure and balance of its ecosystem.

Example of a keystone species.

Wolves in Yellowstone—control deer, restore balance.

What are limiting factors?

Conditions that limit population growth or survival.

Name three limiting factors for plants.

Light, water, temperature.

Name three limiting factors for animals.

Food, space, water.

What is a range of tolerance?

The range of environmental conditions where an organism can survive.

What are the zones in a tolerance range?

Optimal range, stress zones, and zones of intolerance.

What happens if an organism is outside its range of tolerance?

It experiences stress or dies.

Define succession.

The natural, gradual change in an ecosystem over time.

What is primary succession?

Succession that begins where no soil exists, like after lava flow or glaciers.

What is secondary succession?

Succession after a disturbance where soil remains, like after a fire.

What are pioneer species?

First organisms to colonize a barren area, like lichens or mosses.

What is a climax community?

A stable, mature ecosystem that forms at the end of succession.

What happens after a forest fire?

Secondary succession occurs—grasses grow first, then shrubs, then trees.

What is weather?

Day-to-day conditions of Earth’s atmosphere.

What is climate?

The average long-term weather patterns of a region.

What two abiotic factors mainly determine land biomes?

Temperature and precipitation.

Give an example of how abiotic factors affect biotic factors.

Cacti survive in deserts because they can store water; frogs cannot.

Why are aquatic ecosystems hard to divide into biomes?

They depend on depth, flow, temperature, and nutrients, not just climate.

What is the photic zone?

The sunlit region near the water surface where photosynthesis occurs.

What is the aphotic zone?

The dark, deep zone where no sunlight reaches.

What is an estuary?

Where a river meets the sea; mix of fresh and saltwater.

Why are estuaries important?

They serve as nurseries for fish and shellfish.

What drives ocean circulation?

Wind, water temperature, and salinity differences.

What is homeostasis in ecosystems?

The tendency to maintain balance and stability like a living organism.