The Biosphere Basics
What is the biosphere?
The part of Earth where life exists, including land, water, and air.
Give one example of a biotic factor.
Any living thing: plants, animals, fungi, bacteria, etc.
What is weather?
Day-to-day conditions of the atmosphere.
What two factors determine a biome’s climate?
Temperature and precipitation
What is the difference between freshwater and marine ecosystems?
Freshwater has low salt; marine has high salt content.
What are the levels of organization from smallest to largest?
Individual → Population → Community → Ecosystem → Biome → Biosphere
Give one example of an abiotic factor.
Sunlight, water, soil, temperature, or air.
What is climate?
The average year-after-year pattern of temperature and precipitation in a region.
Which biome is hot, wet, and has the most biodiversity?
Tropical Rainforest
What is an estuary?
A place where freshwater and saltwater mix. It is also a nursery for animals.
What is ecology?
The study of interactions among organisms and between organisms and their environment.
How can abiotic factors affect biotic factors?
They influence where organisms can live and grow (ex: temperature affects plant types).
What is the main energy source that drives Earth’s climate system?
The Sun ☀️
Which biome is dry, with little rain and plants like cacti?
Desert
What abiotic factor affects aquatic ecosystems the most?
Depth, temperature, light, and salinity.
What do we call living parts of an ecosystem?
Biotic factors
How might a change in one abiotic factor—like temperature or rainfall—affect an ecosystem?
It can change which organisms survive there; for example, less rainfall may cause plants to die, leading animals to migrate or die off too.
Why do areas near the equator receive more sunlight?
Because sunlight hits the equator more directly than at the poles.
Which biome has four seasons and broadleaf trees?
Temperate Forest
Why do deeper ocean zones have less biodiversity than shallow zones?
Because sunlight can’t reach deep waters, so less photosynthesis occurs and less energy is available for life.
What do we call nonliving parts of an ecosystem?
Abiotic factors
Explain how biotic and abiotic factors work together to keep an ecosystem balanced.
Biotic factors depend on abiotic factors for survival (sunlight → plants → animals), and together they cycle energy and nutrients through the system.
What effect do ocean currents have on climate?
They transport heat around the globe, warming or cooling nearby land.
Which biome is cold, treeless, and has permafrost?
Tundra
How do human activities—like pollution or overfishing—impact aquatic ecosystems?
They disrupt food webs, reduce oxygen levels, harm species populations, and can destroy habitats like coral reefs and wetlands.