THE SCIENCE OF LIFE

1. THE SCIENCE OF LIFE Modern Biology CHAPTER 1

2. In your notebook, respond to the following questions: “Why do we study Biology?” “What is the goal of science?” Do now:

3. The goal of science is to: investigate and understand the natural world. explain events in the natural world. use those explanations to make useful predictions. Science – Learning About the World

4. Section 1-1 unifying themes of biology

5. Biology - The Study of Life BIOLOGY-the study of all living things. EXAMPLES OF SPECIFIC AREAS: • Histology-the study cells and tissues • Genetics-the study of how traits are inherited • Molecular biology-how organisms function on the molecular level • Ecology-how organisms interact.

6. Biology - The Study of Life ORGANISMS-living things • EXAMPLES: • Plants • Insects • Humans • Bacteria

7. Biology is unified by certain themes (patterns that connect living things) Evolution Reproduction and Inheritance Development Cell Structure and Function Matter, energy and organization Interdependence of organisms *Science & Society 6 Major Themes of Biology

8. Evolution-population of organism changes over generations (time). 1. Evolution

9. All organisms come from existing organisms. Transfer hereditary information in the form of deoxyribonucleic acid (DNA). Can be: ASEXUAL REPRODUCTION-only one organism’s DNA is used. Offspring is identical to parent. EXAMPLE: bacteria dividing SEXUAL REPRODUCTION-DNA from 2 organisms is combined. Offspring is different from both parents and from any other offspring EXAMPLE: humans having a baby Egg and sperm  zygote (fertilized egg). 2. Reproduction & Inheritance

10. This baby has inherited some traits from its mom and some from its dad…it may look similar to one or both of them, but its DNA is a combination of the two! 2. Reproduction & Inheritance

11. All organisms are made of cells. UNICELLULAR-made of only one cell (amoeba, paramecium) MULTICELLULAR-made up of many different types of cells working together (tree, spider, shark). DEVELOPMENT-process where a zygote (combined sperm and egg) becomes a mature (adult) individual. 3. Cell structure & function

12. 3. Cell structure & function

13. The structure (way an organism is put together) is connected to its function (how it works). EXAMPLE: Bird’s wing Human hand Stomach Muscle cell **The Cell is the basic unit of life. All organisms are made of and develop from cells. 3. Cell structure & function

14. The structure (way an organism is put together) is connected to its function (how it works). EXAMPLE: Bird’s wing Human hand Stomach Muscle cell **The Cell is basic unit of life. All organisms are made of and develop from cells. 3. Cell structure & function

15. 3. Cell structure & function

16. Living things must maintain stable internal conditions to survive. Homeostasis- stable level of internal conditions found in all living cells. EXAMPLES: temperature water content food intake 4. Stability & homeostasis

17. All organisms obtain, use and transfer energy. ALL energy comes from the SUN. Autotrophs-organisms that can get energy by producing their own food. EXAMPLES: plants and some unicellular organisms Heteroptrophs-organisms that must get energy by eating other organisms EXAMPLES: some unicellular organisms, all animals and fungi 5. matter, energy & organization

18. Ecology-the study of how organisms interact with each other and with their environment. All organisms need substances (nutrients, water, gases) from their environment. 6. Interdependence of organisms

19. Knowledge from science can be used to improve life. Example: polio vaccine, penicillin. Science & society

20. IS IT ALIVE…OR IS IT??

21. In your notebook, respond to the following: Suppose you discovered an unidentified object on your way home from school. How would you determine if it is a living or a nonliving thing? DO NOW:

22. Sect 1-2 the world of biology

23. All organisms, no matter how different, have certain characteristics in common – THE CHARACTERISTICS OF LIFE ! The characteristics of life

24. All living things are composed of cells… 1. Made of cells

25. All living things are highly organized… Organized at cellular and molecular level. Cell structures (organelles) carry out specific functions. Multicellular organisms may contain many types of cells, each type carrying out one job (Specialized-carry out one set of functions). 2. organization

26. In multicellular organisms, cells and groups of cells (tissues) are organized by their function Cellstissues Tissuesorgans Organs  systems SystemsORGANISM 2. organization

27. All living things use energy… All organisms use energy to grow and make repairs. Metabolism-all the chemical reactions that take place in a living organism. 3. Energy use

28. All living things respond to their environment… Response-reaction to input from the world. May be simple or complex. EXAMPLE: gazelle runs away from a lion. 4. Respond to environment

29. All living things grow and develop… As cells divide and get larger, the organism becomes bigger. 5. growth

30. All living things reproduce… Create more of their own species. Essential to the survival of the species…NOT of the reproducing organism. 6. reproduction

31. All living things maintain stable internal conditions…(Homeostasis) EXAMPLE: water balance, ph, gas exchange…birds feathers fluffing up in cold weather . 7. Maintain homeostasis

32. Compare an icicle to a carrot. Make a chart that lists the characteristics of life. Decide which of them that each meets and use the chart to decide which is alive and which is not. Explain. Check for understanding

33. Section 1-3 scientific methods

34. Watch this at Home How simple ideas lead to scientific discovery

35. Do Now Respond to the following in your notebook: How do we investigate and acquire knowledge in science?

36. What do you see in this picture?

37. The Scientific Method What is it?? Scientific Method a systematic way of developing an answer to a question or problem through experimentation.

38. The Scientific Method The Scientific Method has 6 steps: • Observation (Asking questions & collecting data) • Hypothesis (explains their observations and can be tested!!) • Experiment (testing your hypothesis) • Organizing Data • Conclusion • Communication

39. The Scientific Method

40. Step 1 - Observation • Use the 5 senses to perceive objects or events. • Asking a question • Based on observations; one or more questions are generated.

41. Step 2 – Forming a Hypothesis • Once a specific question has been asked, a scientist can think about possible answers to the question. • Hypothesis-a possible explanation for what was observed that must be able to be tested. • May be disproven as new data is collected. • If/then statement-often written in this form. • Example: If the amount of sunlight is affecting the growth of my plants, then plants receiving more sunlight should grow at a faster rate.

42. Step 3 - Experimenting • A test of the hypothesis by gathering data under controlled conditions. • Conducting a controlled experiment. • Data-observation and measurements gathered during the experiment. • Based on a comparison of a control group with an experimental group.

43. Step 3 - Experimenting • Both are identical except for one factor (independent variable). • Observations and measurements are taken for a particular factor (dependent variable) in both groups. • Driven by/or results from independent variable.

44. The Scientific Method What are the parts of an experiment? • Control Group- in an experiment, the group is the standard of comparison with the other group, does not receive the experimental factor, the “normal” group. • Experimental Group- in an experiment, group exposed to the experimental factor, but is otherwise IDENTICAL to the control group.

45. The Scientific Method What are the parts of an experiment? Independent Variable-the factor deliberately changed by the scientist; the one factor different between the groups. **Independent variable causes a change in what you are measuring – the dependent variable** Dependent Variable-the one thing that is measured in the experiment, directly influenced by the independent variable. • Outcome variable measured each time the independent variable is changed.

46. Step 4 – Organizing Data • Involves placing observations and measurements (data) in order. • Charts, tables, graphs or maps.

47. Step 4 – Organizing Data • Analyze data • Determine if the data has meaning • Is the data reliable (trustworthy)? • If Yes---run the experiment again…and again! • If NO---make a new hypothesis and run experiment again.

48. Step 5 - Conclusion • Conclusions are made on the basis of facts, not observations • Often drawn from data gathered from a study or experiment • Shouldsupport the hypothesis • Should be re-testable

49. Step 6 - Communication • Scientists must share the results of their studies with other scientists (peers) • Publishfindings in journals • Present their findings at scientific meetings • Scientists must be unbiased • Should not tamper with their data • Only publish & report tested & proven ideas

50. Step 6 - Communication • Sharing of information is essential to scientific process • Subject to examination and verification by other scientists • Allows scientists to build on the work of others