1. 18.3 Kingdom & Domains I. Updating Classification Systems
A. From ___ to ___ Kingdoms
1. only _________& __________ to start
2. by 1950 ____________, __________, & ________ added
B. ___ kingdoms
1. In 1990’s Kingdom ________ questioned
2. Then split into ____________ & _______________

3. II. The Three Domain System
A. Major _________________
1. Cell type: ____________ or __________
2. Cell Walls: _________ or __________
3. Body Type: __________ or __________
4. Nutrition: ___________ or ___________
B. Domain Bacteria
1. equivalent to Kingdom ______________
2. prokaryotes that have a strong exterior ______ & a unique __________ system

4. 3. All similar in structure, with no internal ________________.
4. Most abundant ____________ on Earth & found in every _______________.
C. Domain __________
1. equivalent to Kingdom ______________.
2. chemically unique ______ _______ & __________ , & a unique genetic system
3. evolved in a separate lineage from ___________ early in Earth’s history
4. some archaea eventually gave rise to _____________.

5. 5. Were first found in __________ environments
a. ex. - ______ lakes, the _______ ocean, or hot springs that exceeded _____°C.
b. These are called ______________
6. Methanogens live in _________-free environments.
D. Domain Eukarya
1. Made up of Kingdoms ___________,
__________, __________, & _________
2. complex inner structure allowed cells to become ________ than earliest cells.

6. 3. Utilize true multicellularity & _________ reproduction
4. ______________
a. autotrophs that use ______________
b. cell wall is made of ____________
c. More than _________ known species
5. _____________
a. multicellular __________________.
b. lack a rigid cell ________.

7. 6. ___________
a. heterotrophs, mostly _____________
b. cell wall is rigid material called _________
c. more closely related to ___________ than to any other kingdom.
d. More than ____________ known species
7. _______________
a. a “leftover” taxon, so it is a ____________ group.
b. did not descend from a ___________ common ancestor.
c. More recently, biologists have proposed to replace _____________ with several new ______________.