a molecule that is formed when oxygen and haemoglobin combine chemically.
a plant with thick, fleshy leaves in which it stores water.
cells that are formed during secondary growth by the vascular cambium ring just to the inside of...
a clear, colourless solution of hydrogen chloride (HCl) in water. It is a strong and highly...
a disease caused when the body's immune system destroys other body cells.
a small, corky pore or narrow line on the surface of the stem of a woody plant that allows the...