WGU C190 Intro to Biology
,1. Abiotic: Non-living, may be within or made by a living organism.
2. Biotic: Living. Matter is considered if it was ever alive at some point in
time
3. Atom: Smallest level. The basic unit of matter. Consists of a dense nucleus
surrounded by electrons.
4. Molecule: Second level. A chemical structure consisting of at least two atoms
held together by a chemical bond.
5. Macromolecule: Third level. Biologically important molecules that are technically
polymers. Example: DNA.
6. Cell: Fourth level. The fundamental unit of life. Essentially a tiny droplet of water
,and other molecules enclosed by a fluid "skin" or membrane. The smallest and
, simplest entity that possesses all the characteristics of life.
7. Organelle: Fifth level. Compartments inside the cell that contain specific groups
of macromolecules and carry out specific cellular functions. One of these organelles is the nucleus;
it encloses the DNA within the cell.
8. Microorganism: Sixth level. Single-celled life form. Consists of just one cell and
include unicellular organisms such as bacteria and protists.
9. Tissue: Seventh level. Formed when similar cells work together to fulfill the same
detailed function.
10. Organ: Eighth level. Collections of tissues that work together to carry out a
common general function. Present not only in higher level animals but also in plants.
11. Organ System: Ninth level. Consists of functionally related organs. Mammals
,1. Abiotic: Non-living, may be within or made by a living organism.
2. Biotic: Living. Matter is considered if it was ever alive at some point in
time
3. Atom: Smallest level. The basic unit of matter. Consists of a dense nucleus
surrounded by electrons.
4. Molecule: Second level. A chemical structure consisting of at least two atoms
held together by a chemical bond.
5. Macromolecule: Third level. Biologically important molecules that are technically
polymers. Example: DNA.
6. Cell: Fourth level. The fundamental unit of life. Essentially a tiny droplet of water
,and other molecules enclosed by a fluid "skin" or membrane. The smallest and
, simplest entity that possesses all the characteristics of life.
7. Organelle: Fifth level. Compartments inside the cell that contain specific groups
of macromolecules and carry out specific cellular functions. One of these organelles is the nucleus;
it encloses the DNA within the cell.
8. Microorganism: Sixth level. Single-celled life form. Consists of just one cell and
include unicellular organisms such as bacteria and protists.
9. Tissue: Seventh level. Formed when similar cells work together to fulfill the same
detailed function.
10. Organ: Eighth level. Collections of tissues that work together to carry out a
common general function. Present not only in higher level animals but also in plants.
11. Organ System: Ninth level. Consists of functionally related organs. Mammals
