Yahoo Web Search

  1. About 53,700 search results
    • Image courtesy of

      • Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth at least 3.5 billion years ago.
  1. People also ask

    What are the main points of the cell theory?

    What is the cell theory and what does it state?

    What are facts about cell theory?

    What are the 3 principles of cell theory?

  2. › wiki › BiologyBiology - Wikipedia

    3 days ago · Cell theory states that cells are the fundamental units of life, that all living things are composed of one or more cells, and that all cells arise from preexisting cells through cell division. Most cells are very small, with diameters ranging from 1 to 100 micrometers and are therefore only visible under a light or electron microscope.

  3. › wiki › Solar_cellSolar cell - Wikipedia

    4 days ago · A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current , voltage , or resistance , vary when exposed to light.

  4. 5 days ago · Immune system. This is the latest accepted revision, reviewed on 4 December 2021. The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them ...

  5. › wiki › BacteriaBacteria - Wikipedia

    3 days ago · Bacteria can be classified on the basis of cell structure, cellular metabolism or on differences in cell components, such as DNA, fatty acids, pigments, antigens and quinones. While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between distinct ...

    • Bacteria
  6. › wiki › MutationMutation - Wikipedia

    5 days ago · A newer theory suggests that the selective pressure on the CCR5 Delta 32 mutation was caused by smallpox instead of the bubonic plague. Malaria resistance: An example of a harmful mutation is sickle-cell disease, a blood disorder in which the body produces an abnormal type of the oxygen-carrying substance hemoglobin in the red blood cells.

  1. People also search for