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. Eubacteria 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?

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.