15 source-checked questions. A library, not live AI.
Water continually moves between the atmosphere, land, oceans and underground stores. It can change between liquid, solid and gas.
Rain can soak into soil, flow into rivers and later return to the air.
Source: USGS: Water cycle. Checked 7 October 2026.
Energy from the Sun and gravity drive much of the natural movement of water. Sunlight supplies energy for evaporation, and gravity moves water downward.
Rain falls and rivers flow downhill under gravity.
Source: USGS: Water cycle. Checked 7 October 2026.
Water vapour cools and condenses into tiny liquid droplets; clouds can also contain ice crystals.
A cloud contains tiny droplets or ice, rather than being only invisible water vapour.
Source: USGS: Condensation. Checked 7 October 2026.
Precipitation is water falling from the atmosphere to the surface, such as rain, snow or hail.
Rain reaching a field is one form of precipitation.
Source: USGS: Water cycle. Checked 7 October 2026.
Some water soaks into the ground and recharges underground water stores. It can move through spaces in soil and rock.
After rain, some water enters the ground rather than running into a drain.
Source: USGS: Water cycle. Checked 7 October 2026.
They use light energy, water and carbon dioxide to make energy-storing carbohydrates through photosynthesis.
A leaf uses light to help build sugars. Soil minerals matter too, but are not the plant's main sugar supply.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
Carbon dioxide supplies carbon for building carbohydrates during photosynthesis.
Carbon dioxide from the air enters leaves through small openings.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
Oxygen is released during photosynthesis as plants use light energy to process water and carbon dioxide.
Photosynthetic organisms contribute oxygen to the environment.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
Chlorophyll is a pigment that absorbs light energy used in photosynthesis.
Chlorophyll in leaf cells helps start the light-dependent reactions.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
It happens in chloroplasts, cell structures that contain the machinery for photosynthesis.
Many cells inside a leaf contain chloroplasts.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
No. Algae and cyanobacteria can also carry out photosynthesis.
Photosynthetic algae live in water.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.
Roots usually anchor a plant and absorb water and minerals. Different plants have different root forms.
A root system helps hold a plant in place in soil.
Source: OpenStax: Plant body. Checked 7 October 2026.
Xylem is the plant tissue that carries water and dissolved minerals from the roots to other parts of the plant.
Water taken in by roots can reach leaves through xylem.
Source: OpenStax: Plant body. Checked 7 October 2026.
Phloem transports sugars and other organic compounds from places where they are made to places where they are needed.
Sugar made in a leaf can be transported to another part of the plant.
Source: OpenStax: Plant body. Checked 7 October 2026.
Photosynthesis stores light energy in carbohydrates. That chemical energy can pass to animals that eat plants and to animals that eat those animals.
Grass, a grazing animal and its predator illustrate a path for energy.
Source: OpenStax: Photosynthesis. Checked 7 October 2026.