1. Ch 1: The Science of Biology Studying Life What is Science?Science in Context

2. A. What Science Is and Is Not 1.The goal of science is to investigate and understand the natural world through explanations. 2. Science – an organized way of gathering and analyzing evidence to learn about the natural world. a. Science refers to the body of knowledge built up over time. 3. Why is there uncertainty in science?

3. B. Thinking like a Scientist: Scientific Methodology 1. Observation – the act of noticing and describing events or processes in a careful, orderly way using the five senses 2. Inference – interpretation based on prior knowledge (what scientists already know) or experience “ a logical conclusion”. StatementObservation Inference Object A is round and orange. Object A is a basketball. Object C is round and black and white. Object C is larger than Object B. Object B is smooth. Object B is a table-tennis ball. Each object is used in a different sport. Object C is a soccer ball. X X X X X X X X What is object C?

4. Explaining and Interpreting Evidence 1. Hypothesis – proposed scientific explanation for a set of observations to make inferences. 2. A hypothesis can result from prior knowledge, inference, or creative imagination 3. A hypothesis should be testable Science as a Way of Knowing 1. Science is an ongoing process – it is always changing 2. Good scientists are constantly questioning 3. Having an open-mind is critical to discovery

5. Designing Controlled Experiment 1. Ask a Question 2.Form a hypothesis – a statement that can be tested Always written has an “if” “then” “because” statement. 3. Setting up a controlled experiment- investigation in which only a single factor is tested a. Experimental group – contains factor being tested b. Control group– does not contain the factor being tested c. Variables 1. independent variable – also known as the manipulated variable – the change 2. dependent variable – also known as the responding variable – what you are measuring How Scientists Work

6. 4. Recording and Analyzing data (experimental observations) a. Tables, Graphs, Charts, Etc. b. Qualitative – involves physical description e.g. Blond hair, green eyes c. Quantitative – uses numbers or measurements e.g. 35 mm, 12 tables 5. Drawing a conclusion * Is hypothesis supported or refuted 6. Publishing and Repeating the work a. Experiment is only valid if it can be repeated b. Communication is essential

7. Mystery Worms A teacher collected some beetles from a rotting log and placed them in a container of dry oatmeal in her classroom. She kept the box covered with a light cloth so that the beetles could not escape. She also asked one of her students to add potato and apple pieces once a week to provide food and moisture for the beetles. After several weeks, the student reported that there were some strange- looking, wormlike organisms in the container.

8. Mystery Worms Think- pair-share 1.Formulate a hypothesis that might explain the presence of the “worms” in the container. 2.Explain in detail how you could test your hypothesis. 3.Identify the variables in your proposed experiment. 4.Identify the control group in your experiment. 5.What data would you collect during your experiment?

9. OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from meat Uncovered jars Covered jars Several days pass Maggots appear No maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Section 1-2 Figure 1-8 Redi’s Experiment on Spontaneous Generation

10. Publishing and Repeating the work 1. Needham’s Test of Redi’s findings a. Possible due to Leeuwenhoek’s discovery of microscopic world. “animalcules” b. Sealed a bottle of gravy and heated it. Uses broth as the medium for life. c. Life was in it so life comes from the gravy. d. Believes he has proven spontaneous generation. 2. Spallanzani’s Test of Redi’s work a. Improves upon Needham’s design, thought he did not heat them enough. b. Concludes spontaneous generation is not possible

11. Gravy is boiled. Flask is open. Gravy is teeming with microorganisms. Gravy is boiled. Flask is sealed. Gravy is free of microorganisms. Section 1-2 Figure 1-10 Spallanzani’s Experiment

12. 3. Pasteur’s test of Spontaneous generation a. Sets out to finally disprove the idea of spontaneous generation. b. Designs a special flask that allows air to reach the medium. c. Made significant contributions to the scientific community. d. Biogenesis – idea that living things come from other living things. Publishing and Repeating the work Broth is boiled.Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms.

13. Designing an Experiment State the Problem Form a Hypothesis Set Up a Controlled Experiment Record Results Analyze Results Draw a Conclusion Publish Results Theory – a well tested explanation that unifies a broad range of observations and hypotheses, and enables scientist to make accurate predications about new situations. Bias – a particular preference or point of view that is personal, rather than scientific. Want to avoid this!

14. 1–3 Studying Life BIO = life logy = the study of Biology= the science that seeks to understand the living world A. Characteristics of Living ThingsCharacteristics of Living Things 1. Made Up of units called cells a.cell –a collection of living material enclosed by a barrier that separates the cell from its surroundings. - Smallest unit of an organism. b. unicellular- one celled organism c.multicellular – many celled organism Introduction to cells video

15. 2. Reproduction - to produce new similar organisms a. Sexual -2 cells from different parents unite b. Asexual - new organism has 1 parent. One organism splits to form 2. Organism produces offspring identical to itself. 3. Based on a Universal Genetic Code a. The offspring will resemble the parents e.g. Dogs produce dogs b. DNA = deoxyribonucleic acid

16. 4. Growth and Development a. Growth – an increase in size b. Development – cells divide and change their shape and structure according to their intended function. * Give an example of a rapid and dramatic change in an animal*

17. 5. Need materials and energy - to grow, develop, reproduce, and to just stay alive! a. anabolism : making complex substances from simple substances b. catabolism : breaking down complex substances into simpler ones. c. metabolism : The building up and breaking down of substances in an organism, as it carries out its life processes.

18. 6. Respond to the environment a. Stimulus : Anything in the environment that can cause an organism to react. 7. Maintaining Internal Balance (stable environment) a. Homeostasis – Steady state b. Organisms maintain constant internal conditions despite the external conditions 8. Evolution – change over time * important for a group’s survival in a changing world.

19. CharacteristicExamples Living things are made up of units called cells. Living things reproduce. Living things are based on a universal genetic code. Living things grow and develop. Living things obtain and use materials and energy. Living things respond to their environment. Living things maintain a stable internal environment. Taken as a group, living things change over time. Many microorganisms consist of only a single cell. Animals and trees are multicellular. Maple trees reproduce sexually. A hydra can reproduce asexually by budding. Flies produce flies. Dogs produce dogs. Seeds from maple trees produce maple trees. Flies begin life as eggs, then become maggots, and then become adult flies. Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat. Leaves and stems of plants grow toward light. Despite changes in the temperature of the environment, a robin maintains a constant body temperature. Plants that live in the desert survive because they have become adapted to the conditions of the desert.

20. Branches of Biology 1.Biology is broken down into many fields such as botany, microbiology, ethology, and zoology. 2.Living things can be studied at various levels of organization as well.

21. Biosphere Ecosystem Community Population The part of Earth that contains all ecosystems Community and its nonliving surroundings Populations that live together in a defined area Group of organisms of one type that live in the same area Biosphere Hawk, snake, bison, prairie dog, grass, stream, rocks, air Hawk, snake, bison, prairie dog, grass Bison herd Organism Groups of Cells Molecules Individual living thing Tissues, organs, and organ systems Smallest functional unit of life Groups of atoms; smallest unit of most chemical compounds Bison Nervous tissue Nervous system Brain Nerve cell Water DNA

22. Scientific Measurement 1. Decimal system- based on powers of 10 2. AKA International system of units or SI 3. Common system of measurement for scientists around the world

23. Conversions between large and small quantities K H Dk U d c m This chart tells you two things:  How many places to move the decimal  In what direction to move the decimal

24. KH DkUdcm Examples: 4.51 kg = ________g 4.51 kg 4587m = _________mm 4587m 1.23 mL = ________L 1.23 mL

25. Answers… 4.51 kg = 4510 g 4 5 10

26. 4587m = 4,587,000mm 4587 000

27. 1.23 mL = 0.00123 L