Chapter 15 Phylogenies and Classifying Diversity

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

• Taxonomy – the science of classifying organisms based on features they share.

• Taxonomist – a scientist who classifies and assigns scientific names to organisms.

• Prokaryotes – cells that do not have a nucleus or other organelles.

• Eukaryotes – cells with a nucleus and other organelles.

• Organelle – a membrane bound structure found within a cell; usually performs a certain function.

3 Domain System

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

Domain Bacteria

(Eubacteria)

Domain Archaea

(Archaebacteria)

Domain Eukarya

Kingdoms

• Protista

• Fungi

• Plantae

• Animalia

• True bacteria

• Simplest single cells that carry out all basic life activities.

• Prokaryotic

• Live in soil, water and air

• May or may not perform photosynthesis.

• Some bacteria are helpful and some bacteria are harmful.

EubacteriaEubacteriaCh 15, Lesson 1 How Do Scientists Classify Living Things?

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

Examples of Bacteria

Archaebacteria• Prokaryotic

• Single celled

• Autotrophic – make their own food from chemicals

• Most live in extreme environments – swamps, hot springs, thermal deep sea vents

• Their genes are more similar to Eukaroytes than Prokaryotes

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

Eukarya –

Eukaryotes –

• Larger than prokaryotes

• Some are unicellular celled organisms.

• Some such as algae are multicellular.

• Others have many cells that do different tasks.

• Every cell has a nucleus and other organelles.

Ch 15, Lesson 1 How Do Scientists Classify Living Things?

• Non-Living Viruses– Since viruses are non-living, they are not classified in a

domain.

– Made of genetic material surrounded by a protein coat.

– Viruses are specific. For example, plant viruses infect certain plant cells, but not animal cells.

– Scientists classify viruses by the kind of organism they infect, they shape, and the molecules they use.