1. Chapter 1: Classifying and Exploring Life Study Guide

2. Organism- things that have all the characteristics of life.
What 2 scientists invented the early microscopes? Robert Hooke and Leeuwenhoek
How does unicellular organisms grow? They grow as the cell increases in size.
Define dichotomous key- series of descriptions arranged in pairs that leads the user to the identification of an unknown organism.
Why would you use a dichotomous key? How are they important? I would use a dichotomous key because it would be the easiest and most efficient to use. They are important because they help you identify an organism.
Dichotomous keys are divided into steps and have how many descriptions next to the steps? 2
What is external stimuli? How you respond to changes in the environment.
Give an example of external stimuli. Light, temperature, sights, sounds, & smells

3. 9. How many groups did Aristotle use to classify organisms
9. How many groups did Aristotle use to classify organisms? What were the groups? 2 groups- Plants & Animals 10. Define homeostasis- an organism’s ability to maintain steady internal conditions when outside conditions change. 11. What are similar genera grouped into? families 12. What is internal stimuli? How you react to an internal change in the environment. 13. Give an example of internal stimuli. Hunger & Thirst 14. How many kingdoms are there today? Are scientific names the same all over the world? YES 16. Each species has its own scientific name. 17. How does an organism grow? They increase in size. 18. Give an example of how your body responds to a stimulus. If you’re hungry, you eat something.

4. 19. The first name of the organism’s scientific name is the genus. 20
19. The first name of the organism’s scientific name is the genus. 20. Define systematics- current classification method; uses all the evidence that is known about an organism to classify them. 21. What does scientific names of organisms consist of? Genus and specific name 22. What is the scientific name of a brown bear? Ursus Arctos 23. Define cladogram- branched diagram that shows the relationships among organisms, including common ancestors. 24. What is a cladogram similar too? Family Tree 25. What do people in the health care fields use microscopes for? View surgical field, analyze body fluids and determine whether tissue is healthy or diseased. 26. What type of microscope would you use to see something 1500 times larger? light 27. Electron microscopes-use a magnetic field to focus a beam of electrons through an object or onto an object’s surface

5. 28. Define cells- smallest unit of life 29
28. Define cells- smallest unit of life 29. When was the first microscope invented? Mid 1600s 30. Can non-living things have characteristics of life? Yes, they can have some but not all of the characteristics living organism have. 31. What is an example of growth and development? A tadpole loses its tail, grows legs, & becomes an adult frog. 32. All living things have structures that perform specific functions. 33. Define binomial nomenclature- gives each organism a two-word scientific name. 34. Define genus- group of similar species.