Cell : It is smallest unit of human body and other multicellular organisms.
Cell Membrane: It is outermost fluid covering around a cell. It is made up of phospholipids and proteins.
Tissue: composed of a group of cells with similar structure and performing same functions e.g. epithelial, connective tissues.
Organ: is larger structure composed of several types of tissues and perform specific function. e.g. stomach contains epithelium, muscular and connective tissue and performs digestive action.
System: is a group of several organs performing several functions of related nature. e.g. digestive system composed of organs like mouth, tongue, teeth, oesophagus, stomach and intestines etc.
Myocyte: cell showing contractile function of muscle cell e.g. skeletal muscle fibre, smooth muscle cell and cardiac myocyte.
Neuron: cell of nervous system (brain, spinal cord).
Osteocyte: cell of bones.
Chondrocyte: cells of cartilages.
Hepatocyte: cells of liver.
Erythrocyte: red blood cells.
Leucocytes: white blood cells.
Thrombocytes: platelet cells.
Oocyte: female germ cells.
Sperm: male germ cells.
Endothelium: lining tissue of blood vessels.
Melanocyte: Pigmented cell of skin.
Mitosis : is multiplication of cell in which parent cell divides into two daughter cells with same number of chromosomes. Occur in somatic cells.
Meiosis: is multiplication of cell in which parent cell divides into daughter cells with half number of chromosomes. It occurs in gametic cells.
Somatic Cell: cells of general body (except germ cells) are called somatic cells. They divide by mitosis.
Gametic Cell: are cells (primary spermatocyte and primary oocyte) of sex glands i.e. testes and ovaries which divides by meiosis.