All living things are made up of cells. This concept, called the cell theory, was discovered by two German biologists, Theodor Schwann and Matthias Schleiden, and was compiled in a book by Rudolf Virchow.Know More
In the 17th century, Robert Hooke sliced up a piece of cork and examined the pieces in a microscope. He observed objects that looked like little jail cells, and he named these objects "cells."
Hooke's observations paved the way for the development of the cell theory, which states that cells are the building blocks of all life, making up the structure of organisms and performing all the functions within organisms. Another part of the cell theory discusses that cells can only arise from pre-existing cells.Learn more about Cells
All cells have at least three common features: a cell membrane, cytoplasm and DNA. Every cell has a selectively permeable cell membrane that allows some materials to pass in and out of the cell, and contains the water-based solution cytoplasm. Even if lacking a nucleus, all cells also contain DNA.Full Answer >
Cells need several things to survive, including energy, protein, oxygen, carbon dioxide, vitamins and minerals. A cell's requirements for survival can vary from organism to organism. Plants need carbon dioxide to create energy, whereas humans need oxygen.Full Answer >
Ultimately, the energy that powers every living thing on Earth begins with nuclear fusion. Life on Earth depends on the sun's light and warmth, which comes from the fusion of hydrogen atoms in the star's core. Without this power source, the Earth would be a barren wasteland.Full Answer >
According to the Biology Department at Indiana University Southeast, all four of the primary biomolecules contain carbon. This includes nucleic acids, lipids, carbohydrates and proteins. All four of these biomolecules are large and complex molecules that take advantage of the ability for carbon atoms to form long chains.Full Answer >