The Atmosphere
What gas do humans breathe in from the atmosphere?
Oxygen
What is the name for all the water on Earth?
The hydrosphere
What are the three main layers of the Earth?
Crust, mantle, core
What does biodiversity mean?
The variety of living things on Earth.
What is the basic unit of life?
The cell
Name two gases that make up most of the atmosphere?
Nitrogen and Oxygen
What are the three states of water in nature?
Solid, liquid, gas
What is the difference between oceanic crust and continental crust?
Oceanic crust is thinner and denser; continental crust is thicker and lighter
Why is biodiversity important?
It helps ecosystems stay balanced and provides resources for humans
Name two differences between plant and animal cells.
Plants have a cell wall and chloroplasts; animals do not.
What is the function of the ozone layer?
It protects us from harmful UV rays.
How does water move through the water cycle?
Evaporation, condensation, precipitation, and collection
How do earthquakes happen?
Tectonic plates move and release energy.
What is an endangered species?
A species at risk of extinction.
What is photosynthesis?
The process plants use to make food using sunlight, water, and carbon dioxide.
Why is the atmosphere important for life on Earth?
It provides oxygen, protects from radiation, and regulates temperature.
Why is the ocean salty?
Because of minerals and salts from rocks and rivers.
What are the differences between magma and lava?
Magma is underground; lava is magma that reaches the surface.
How do human activities affect biodiversity?
Deforestation, pollution, and climate change can harm species.
What are the five kingdoms of living things?
Animals, plants, fungi, protists, monera
How does the greenhouse effect help keep Earth warm?
It traps heat from the Sun, preventing it from escaping back into space.
What is groundwater, and why is it important?
Water stored underground in rocks; it provides drinking water and supports ecosystems.
How do volcanoes form?
Magma rises through cracks in the Earth's crust and erupts as lava.
What can we do to protect biodiversity?
Recycle, conserve energy, protect natural habitats, and reduce pollution.
Why are microorganisms important in nature?
They help decompose waste, make oxygen, and can be used in food and medicine.