Classification Notes

1. Classification Notes Name ________________________ Date ______________ Pd _____

2. Scientists Classify Living Things • Scientists develop systems for classifying living things. • Scientists classify millions of species • Classification and Taxonomy: • Classification – the process of arranging organisms into groups based on similarities • A good system of classification allows you to organize a large amount of information so it is easy to understand • Taxonomy – the science of naming and classifying organisms • A good system of taxonomy allows people to communicate about organisms

3. Using Classification • Using Classification: • Scientists use similarities and differences among species to classify • Appearance, DNA, etc… • Classification systems help identify unfamiliar organisms • The more characteristics two organisms share, the more similar their names should be in the classification system.

4. Taxonomists • Taxonomists study biological relationships • Taxonomist– scientist who classifies and names organisms based on their similarities and differences • Taxonomists study the relationships between species • To determine how to classify organisms, scientists compare a variety of traits • Physical Evidence • Scientists compare color, size, weight, and how groups of organisms obtain energy to help classify them • Scientists can also compare and measure fossilized bone to classify organisms and also relate organisms to common ancestors through evolution. • Genetic Evidence • Scientists can catalog and compare DNA between organisms to classify them

5. Identifying Organisms • Scientists use dichotomous keys and field guides to help people identify organisms • Dichotomous keys – asks a series of questions that can be answered in only two ways • When using a dichotomous key, each answer leads to another question which will eventually narrow down to the identification of the item • Field Guide – book that includes paintings or photographs to help identify familiar species Next, the statements need to lead the observer to the next step to narrow the identification further: a. wings covered by an exoskeleton ………go to step 2 b. wings not covered by an exoskeleton ……….go to step 3

6. Classification - for Naming Organisms • Organisms can be classified into seven levels of classification • Levels go from broad to specific • The seven levels are (with an example for housecats) • Kingdom (Animalia – the animals) • Phylum (Chordata – animals with backbones) • Class (Mammalia – mammals) • Order (Carnivora – carnivores, animals that eat meat) • Family (Felidae – the cat family) • Genus (Felis – housecats, cougars, and many others) • Species (catus – housecats) • While many organisms can share the more broad levels, less and less animals share the levels as it goes down and only one species will have each Genus and Species combination • To remember the levels: • Kings Play Chess On Fat Green Stools

7. Classification - for Grouping Organisms • Taxonomy changes as scientists make discoveries • Early scientists described two large groups of organisms –plants and animals, however, today, scientists use a system that includes 6 kingdoms and 3 domains • Three Domains: • Domains – groups of organisms based on their basic cell type; there are 3 domains • Domain Bacteria – small, simple cells • Contains the Kingdom Bacteria • Domain Archaea – small, simple cellsthat can survive in extreme conditions • Contains Kingdom Archaea • Domain Eukarya – larger, more complex cells that have a lot of parts • Contains the kingdoms Protista, Fungi, Plantae, and Animalia

8. Classification – for Grouping Organisms • Six Kingdoms • Plantae – plants • Animalia – animals • Protista – very complex unicellular organisms or simple multicellular organisms • Fungi – mushrooms, molds, and yeasts • Archaea – similar to bacteria, but has different structures • Bacteria – simple unicellular organisms