State the Cell theory

Cell theory Contributors to cell theory Cell theory is widely accepted theory that explain the life. There are five contributors to the cell theory: 1. Robert Hooke. 2. Anton van Leeuwenhoek. 3. Matthias Schleiden. 4. Theodor Schwann. 5. Rudolf Virchow. In 1838, German botanist, Matthias Schleiden observed that all plants are made of different kinds […]

Why onions make you cry

Why onions make you cry Onions make us cry because onion releases a chemical called as Propanethiol S-oxide that irritates our eyes. It is sulfur-containing volatile chemical that enters into the eyes and stimulates lachrymal glands to release tears. Propanthial s-oxide is a type of defence mechanism in onion plant that are used to protect […]