Grow and develop
Are made of many cells
Can reproduce
A molecule is two or more atoms bonded together chemically. An atom is the most basic unit of matter. When atoms are chemically bonded together with covalent bonds, molecules are formed. Molecules can be very small like water molecules or extremely large like proteins such as hemoglobin.
It is part of the Vitamin B group. In some people, it causes their urine to turn a yellowish-orange color.
1. Infected needles
2. Insect bite
3. Organ transplant
4. Blood transfusion
