If your notes are out before the bell
If your notes are out before the bell rings you may use them on the quiz!
Standard: B 8 B Categorize organisms using a hierarchical classification system based on similarities and differences shared among groups • Essential Question: How are different organisms or objects sorted into meaningful categories?
• 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 • Sometimes represented as a flow chart
Dichotomous Key
1 a Candy is not hard ………………………. 2 1 b Candy is hard …………………………. . 7 2 a Candy is wrapped ………………………. 3 2 b Candy is not wrapped ……………………. . Ursa gummus 3 a Candy is rounded …………………………. . 4 3 b Candy is not rounded ……………………… 5 4 a Wrapper is all white and semi-transparent……………Saltus taffina 4 b Wrapper is not all white ………………………. 5 5 a Wrapper is mostly brown and white …………………. . Tutus rollus 5 b Wrapper is not brown and white …………………… 6 6 a Wrapper is silver ……………………………Chocolatus cyssan 6 b Wrapper varies in color ………………………Steorra explodus 7 a Candy is spherical (ball-shaped) ………………………. 8 7 b Candy is not spherical ……………………………. 9 8 a Candy is wrapped ……………………………… 11 8 b Candy is not wrapped ………………………. Mandibulus crackus 9 a Wrapper is transparent (see-through) with no writing …………. 10 9 b Wrapper is transparent and tells flavor ……………. Joyous rancheria 10 a Wrapper is clear …………………………. . Mintus stripus 10 b Wrapper is yellow ………………………Rannunculus schotchus 11 a Candy is on a stick ……………………………. . Moronus moronus 11 b Candy is not on a stick …………………………Spherus combustus
Alien Dichotomous Key practice! • Do the best you can to finish before the bell! • How well ya’ll work depends on if we spend time on this tomorrow or not!
Dichotomous Keys: TEKS 7. 11 A A dichotomous key
Dichotomous Key for conifers
Dichotomous Keys: TEKS 7. 11 A Whose shoes? A class dichotomous key
Dichotomous Keys: TEKS 7. 11 A Time to investigate! How do you create a dichotomous key?
Dichotomous Keys: TEKS 7. 11 A Time for Practice! • You and a partner create your own dichotomous key using 12 things you find in your binder/backpack Some hints for writing a dichotomous key: • Write the part name first, then the descriptive term (for example “Tail short and straight, ” not “Short and straight tail”). • Start both choices in a pair with the same word. • Use measurements rather than vague terms like “big” and “little. ” • Use characteristics that are true of all individuals in a group (for example, use fur color only if all individuals have the same color markings).
Make a dichotomous key to identify 6 macroinvertebrates Stone fly larvae Leech Riffle beetle Mayfly larvae Crane fly larvae Dobson fly larvae
Complete the dichotomous key practice by the end of class
- Slides: 14