Science Simulations
Cell division Multicellular organisms like humans are made up of cells of varying shapes and functions. Most cells are so small that they can see them only under a microscope because once they reach a certain … more
Respiratory organ To maintain life, we absorb oxygen from the air. And we export carbon dioxide from the body. Human respiratory organs include the nose, organs, bronchi and lungs. Each bronchus in the lung continues to … more
Why are cells so small? Living cells are constantly exchanging substances with their surroundings. Cells have to absorb nutrients and get waste products out. Most cells, including our body, need to absorb oxygen to get energy. … more