Humans shed about 600,000 particles of skin every hour -- about 1.5 pounds a year. By the age of 70, an average person will have shed more than 100 pounds of skin.

Vinegar is approximately 5% acetic acid in water. The structural formula for acetic acid is CH3COOH.

Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicine, food, and entheogens, as well as their dangers, such as poisoning or infection.

All spiders have eight legs. They also possess a pair of shorter limbs called pedipalps, that in males serve as sex organs. Some spiders seem to have ten legs and not eight, because these pedipalps look like an extra pair of legs.

If you took all the blood vessels out of an average adult and laid them out in a line, it would stretch about 100,000 miles.

Wilhelm Conrad Roentgen earned the first Nobel Prize in Physics for his discovery of electromagnetic radiation in a wavelength range -- commonly known as X-rays today.

Shark and rays are different from other fish because they have no bones. Their skeletons are made of cartilage, which is flexible and durable with about half the normal density of bone.

A mineral is a naturally occurring inorganic solid with a definite chemical composition and an ordered internal structure. Although wood is a naturally occurring solid, it is an organic material, so it is not a mineral.

Often called the "building blocks of life", cells are the basic structural, functional, and biological unit of all known living organisms.

Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name derives.