The Science of Biology. Honors Biology I

Transcription

1 The Science of Biology Honors Biology I

2 1-1 What is Science? Science an organized way of gathering and analyzing evidence about the natural world Deals only with the natural world Collect and organized information in an orderly way Propose explanations bases on evidence, not belief

3 The Goals of science Provide a natural explanation for events in the natural world and use those explanations to understand patterns in nature and make useful predictions about natural events

4 Why is there uncertainty in science? Science rarely proves anything in absolute terms

5 Scientific Methodology: The Heart of Science Involves observing and asking questions, making inferences and forming hypotheses, conducting controlled experiments, collecting and analyzing data, and drawing conclusions

6 Observing and Asking Questions Observation the act of noticing and describing events or processes in a careful, orderly way Inferring and Forming a Hypothesis Inference logical interpretation based on what scientists already know Hypothesis Scientific explanation for a set of observations that can be tested in ways that support or reject it.

7 Designing Controlled Experiments Testing of hypothesis Experiments that keep track of various factors that can change (variables) Controlled Experiment An experiment where a hypothesis is tested by changing only one variable Independent variable variable that is deliberately changed (also called manipulated variable) Dependent variable variable that is observed and that changes in response to the independent variable Control group exposed to the same conditions as the experimental group, except for one independent variable.

8 Collecting and Analyzing Data Data evidence; information gathered from experiments Quantitative Data numbers obtained by counting or measuring Qualitative Data descriptive, involve characteristics that can not be measured

9 Drawing Conclusions Use data as evidence to support, refute, or revise the hypothesis being tested, and draw a valid conclusion

10 1.2 Science in Context Exploration & Discovery: Where Ideas Come From Scientific Attitudes: Good scientists share scientific attitudes, or habits of mind Curiosity asking questions Skepticism question existing ideas Open-mindedness willing to accept different ideas Creativity think creatively to design experiments

11 Practical problems Ideas for specific investigations may arise from practical problems Examples: Should marshes be protected from development? If new houses or farms are located near salt marshes, can they be designed to protect marshes?

12 Role of Technology Scientific discoveries can lead to new technologies Technological advances have a great impact on daily life

13 Communicating Results: Reviewing and Sharing Ideas Peer Review scientific papers are reviewed by anonymous, independent experts Publishing peer reviewed articles in scientific journals allows researchers to share ideas and to test and evaluate each other s work.

14 Scientific Theories Theory well tested explanation that unifies a broad range of observations and hypotheses and that enables scientists to make accurate predictions about new situations Example: Evolutionary theory If a theory is used and tested and supported thoroughly, it becomes the dominant view among scientists Never an absolute truth!!!

15 Science and Society Using science involves understanding its context in society and limitations Science, ethics, and morality Pure science does not include ethical or moral viewpoints Avoiding Bias Bias is a particular preference or point of view that is personal, rather than scientific Understanding and Using Science Science will keep changing Try to understand HOW science works, rather than just believing.

16 1.2 Review 1. List the attitudes that lead scientists to explore and discover. 1. What does it mean to describe a scientist as skeptical? Why is skepticism important? 2. What is peer review? 3. What is a scientific theory? 4. How is the use of science related to its content in society?

17 1-3 Studying Life Biology is the study of life Bios life Ology study of

18 8 Characteristics of Living Things Living things are based on a universal genetic code Contain DNA Living things grow and develop Living things respond to their environment Stimulus signal to which a living things reacts Living things reproduce Sexual Reproduction vs. Asexual Reproduction Living things maintain a stable internal environment Homeostasis maintaining a stable internal environment Living things get and use material and energy Metabolism Chemical reactions through which living things build up or break down materials Taken as a group, living things evolve Living things are made up of cells

19 Big Ideas In Biology Cellular Basis of Life Information and Heredity Matter and Energy Growth, Development and Reproduction Homeostasis Evolution Structure and Function Unity and Diversity of Life Interdependence in Nature biosphere means living planet Science as A way of Knowing

20 Performing Biological Investigations Scientific Measurement Use metric system when collecting data and performing experiments Length meter Mass gram Volume liter (liquid)or cubic centimeter (solid) Temperature Celsius Safety trained to use safe procedures when carrying out investigations

21 1-3 Review 1. List the characteristics that define life 1. Suppose you feel hungry, so you reach for a plum you see in a fruit bowl. Explain how both external and internal stimuli are involved in your action. 2. What are the themes in biology that come up again and again? 3. At what levels do biologists study life? 4. Why do scientists use a common system of measurement?