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.