Classifying and Exploring Life

1. Classifying and Exploring Life Chapter Introduction Lesson 1: Characteristics of Life Lesson 2: Classifying Organisms Lesson 3: Exploring Life Chapter Wrap-Up

2. What are living things, and how can they be classified? Classifying and Exploring Life

3. Dropped Dinner Rolls? Look at the photo at the beginning of the chapter. At first glance, you might think someone dropped dinner rolls on a pile of rocks. These objects might look like dinner rolls, but they’re not. What do you think the objects are? Do you think they are alive? Why do you think they look like this? What are living things, and how can they be classified? Classifying and Exploring Life

4. 1 Characteristics of Life • What do you think?

5. All living things move. The Sun provides energy for almost all organisms on Earth. 1 Characteristics of Life • Do you agree or disagree?

6. Lesson 1: Characteristics of Life An organism is classified as a living thing because it has all the characteristics of life. All living things are organized, grow and develop, reproduce, respond to stimuli, maintain homeostasis, and use energy. Classifying and Exploring Life

7. 1 Characteristics of Life What characteristics do all living things share?

8. organism • cell • unicellular • multicellular • homeostasis • 1 • Characteristics of Life

9. 1 Characteristics of Life What’s missing? Look at the photo at the beginning of the lesson. This toy looks like a dog and can move, but it is a robot. What characteristics are missing to make it alive? Let’s find out.

10. Do you agree or disagree? All living things move. 1 Characteristics of Life Disagree. Movement is not a characteristic of all living things.

11. Do you agree or disagree? The Sun provides energy for almost all organisms on Earth. 1 Characteristics of Life Agree. Most organisms use energy from the Sun for all the processes they perform.

12. What characteristics do all living things share? 1 Characteristics of Life All living things are organized, grow and develop, reproduce, respond to stimuli, maintain homeostasis, and use energy.

13. What are living things, and how can they be classified? All living things have certain characteristics in common and can be classified using several methods. The invention of the microscope has enabled us to explore life further, which has led to changes in classification. Classifying and Exploring Life

14. Lesson 2: Classifying Organisms Living things are classified into different groups based on physical or molecular similarities. Some species are known by many different common names. To avoid confusion, every species has a scientificname based on a system called binomial nomenclature. Classifying and Exploring Life

15. 2 Classifying Organisms • What do you think?

16. A dichotomous key can be used to identify an unknown organism. Physical similarities are the only traits used to classify organisms. 2 Classifying Organisms • Do you agree or disagree?

17. 2 Classifying Organisms What methods are used to classify living things into groups? Why does every species have a scientific name?

18. binomial nomenclature • species • genus • dichotomous key • cladogram • 2 • Classifying Organisms

19. 2 Classifying Organisms Alike or Not? Look at the photo at the beginning of the lesson. In a band, instruments are organized into groups, such as brass and woodwinds. The instruments in a group are alike in many ways. In a similar way, living things are classified into groups. Why are living things classified?

20. Do you agree or disagree? A dichotomous key can be used to identify an unknown organism. 2 Classifying Organisms Agree. The series of questions in a dichotomous key leads to an organism’s identity.

21. Do you agree or disagree? Physical similarities are the only traits used to classify organisms. 2 Classifying Organisms Disagree. Physical similarities, molecular similarities, and ancestral relationships are used to classify organisms.

22. What methods are used to classify living things into groups? 2 Classifying Organisms Living things are classified into different groups based on physical or molecular similarities.

23. Why does every species have a scientific name? 2 Classifying Organisms Some species are known by many different commonnames. To avoid confusion, every species has a scientific name based on a system called binomial nomenclature.

24. 3 Exploring Life • What do you think?

25. Lesson 3: Exploring Life The invention of microscopes allowed scientists to view cells, which enabled them to further explore and classify life. A light microscope uses light and has one or more lenses to enlarge an image up to about 1,500 times its original size. An electron microscope uses a magnetic field to direct beams of electrons, and it enlarges an image 100,000 times or more. Classifying and Exploring Life

26. Most cells are too small to be seen with the unaided eye. Only scientists use microscopes. 3 Exploring Life • Do you agree or disagree?

27. 3 Exploring Life How did microscopes change our ideas about living things? What are the types of microscopes and how do they compare?

28. light microscope • compound microscope • electron microscope • 3 • Exploring Life

29. 3 Exploring Life Giant Insect? Look at the photo at the beginning of the lesson. Although this might look like a giant insect, it is a photo of a small tick taken with a high-powered microscope. This type of microscope can enlarge an image of an object up to 200,000 times. How can seeing an enlarged image of a living thing help you understand life?

30. Do you agree or disagree? Most cells are too small to be seen with the unaided eye. 3 Exploring Life Agree. Most cells need to be magnified hundreds of times in order to be studied.

31. Do you agree or disagree? Only scientists use microscopes. 3 Exploring Life Disagree. Microscopes are used by many different types of people, including forensic scientists, health-care workers, and manufacturing technicians.

32. Do you agree or disagree? Only scientists use microscopes. 3 Exploring Life Disagree. Microscopes are used by many different types of people, including forensic scientists, health-care workers, and manufacturing technicians.

33. How did microscopes change our ideas about living things? 3 Exploring Life The invention of microscopes allowed scientists to view cells, which enabled them to further explore and classify life.

34. What are the types of microscopes and how do they compare? 3 Exploring Life A light microscope uses light and has one or more lenses to enlarge an image up to about 1,500 times itsoriginal size. An electron microscope uses a magnetic field to direct beams of electrons, and it enlarges an image 100,000 times or more.