Bio Chpt 52

What is an organism in ecology?

A single individual living thing

What is a population?

A group of the same species living in one area.

What is a community?

All different populations (species) living in one area.

What is an ecosystem?

A community plus its abiotic (nonliving) environment.

What is a biome?

A large region defined by climate and dominant organisms

What is the biosphere?

All ecosystems on Earth combined

What are biotic factors?

Living parts of an ecosystem (plants, animals, bacteria)

What are abiotic factors?

Nonliving physical and chemical factors like temperature, water, light, and soil.

Why do seasons occur?

Earth’s tilt causes different sunlight angles throughout the year.

How does air circulation affect rainfall?

Warm air rises at the equator, cools, and causes rain; dry air sinks at ~30° latitude creating deserts.

What is the main driver of the water cycle?

Solar energy (evaporation and transpiration)

Why are some areas wet and others dry?

Global air circulation patterns and proximity to oceans determine moisture availability

What characterizes a desert biome?

Very low rainfall, extreme temperature changes, and water-saving adaptations

What characterizes a grassland biome?

Dominated by grasses, moderate rainfall, and frequent fires

What characterizes a tropical forest?

Warm temperatures, high rainfall, and extremely high biodiversity

What characterizes a temperate deciduous forest?

Four seasons, moderate rainfall, and trees that lose leaves in winter

What characterizes a coniferous forest?

Cold climate, cone-bearing trees, and moderate precipitation

What characterizes a tundra biome?

Very cold, low precipitation, permafrost, and low plant diversity

Which terrestrial biome has the highest productivity?

Tropical rainforest (highest biomass and species diversity)

Which other biome has high productivity?

Savannas and temperate forests (moderate to high productivity).

Which biome has the lowest productivity?

Deserts and tundra

What are freshwater biomes?

Lakes, rivers, and estuaries

What are marine biomes?

Ocean regions like coral reefs, pelagic zones, intertidal zones, and abyssal zones

What is an estuary?

A mixing zone where freshwater rivers meet saltwater oceans; very nutrient-rich

What is the intertidal zone?

Area between high and low tide where organisms must tolerate changing conditions

What is the pelagic zone?

Open ocean water away from the shore

What is the abyssal zone?

Deep ocean zone with no sunlight, high pressure, and cold temperatures

why are coral reefs highly productive?

Warm shallow water, sunlight, and complex habitats

What is the photic zone?

Ocean layer where sunlight penetrates and photosynthesis occurs

What is the aphotic zone?

Ocean layer with no sunlight

Why do tropical regions have the highest biodiversity?

Stable climate, high sunlight energy, and consistent rainfall

Why does habitat complexity increase biodiversity?

More niches allow more species to specialize and coexist

What role does time play in biodiversity?

Longer stable periods allow more evolution and speciation

Why are aquatic ecosystems like coral reefs so diverse?

They provide structure, shelter, and many ecological niche