The levels of organization

1. organs

1.1. An organ is a group of tissues in a living organism that has a specific form and function.

1.2. Organs are grouped together into organ systems

1.3. Organ systems perform a specific task

2. organ system

2.1. The human body is made up of several organ systems that work together as one unit callled the organ system

2.2. In the pyramid of life that organizes all of the elements of life into categories, organ systems are nested between an organism and its organs.

2.3. Organ systems are the groups of organs that are within an organism.

3. organism

3.1. An organism is a living thing

3.2. Organisms usually have five basic needs. They need air, water, nutrients (food), energy and a place to live

3.3. Many organisms do not need access to air at all

4. Atoms

4.1. there are 3 parts to an atom: protons neutrons and electrons

4.2. atoms are the smallest thing that make elements

4.3. atoms are mostly empty space

5. molecule

5.1. a single diamond is a single molecule made of carbon atoms

5.2. they can have different shapes

5.3. Metal atoms are bonded to each other through metallic bonding

6. macro molecule

6.1. Proteins, composed of amino acids

6.2. A macromolecule is a very large molecule, such as protein, commonly created by the polymerization of smaller subunits

6.3. the atoms are identical and held by covalent bonds

7. organclles

7.1. An organelle is a specialized cellular structure in eukaryotic cells analogous to an organ in the body.

7.2. Organelles are discrete structures within the cell that perform a specialized function

7.3. Organelles increase the efficiency of cellular processes by concentrating the factors necessary to carry out specific biochemical reactions separate from the rest of the cell

8. cells

8.1. cell is the basic unit of a living organism

8.2. a collection of cells that work together to perform similar functions is called a tissue

8.3. Each kind of cell is structured to perform a highly specialized function.

9. tissues

9.1. tissues are essentially large sheets of cells covering all the surfaces of the body exposed to the outside world and lining the outside of organs

9.2. Human body tissue makes up organs and other body parts.

9.3. There are four main types of tissue: muscle, epithelial, connective and nervous