Chapter one

Objectives for 1.1 State the goals of science Describe the steps used in the scientific method

I. 1.1 what is science? A. What are the goals of science? 1. Science as a Way of knowing Science – organized way of gathering and analyzing evidence about the natural world. 2. Goals of science a) Provide natural explanations for events in natural world b) Aims to use those explanations to understand patterns in nature and make useful predictions about natural events.

3. Science, change, and Uncertainty a) Almost every major scientific discovery raises more questions than it answers b) Uncertainty is part of scientific process c) Science rarely proves anything in absolute terms

B. Scientific Methodology: The heart of Science What procedures are the core of scientific methodology? Observing and asking questions, making inferences and forming hypothesis, conducting controlled experiments, collecting and analyzing data and drawing conclusions. 1. Observing and asking questions Observation- act of noticing and describing events or processes in a careful orderly way

2. 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

3. Designing controlled experiments Controlled experiments – experiment in which only 1 variable is changed a) Controlling variables Independent variable – variable that is deliberately changed in the experiment Dependent variable – variable that is observed and that changes in response to the Independent variable. Do not change more than 1 variable in an experiment at one time!!!!

b) Control and Experimental Groups Control group – exposed to the same conditions as the experimental group except for one independent variable An experiment has a control group and an experimental group. Scientists set up several sets of experiments to reproduce results.

4. Collecting and analyzing data Data – information gathered through observations Qualitative data – descriptive characteristics that cannot be counted Quantitative data - numbers obtained by counting during experiment a) Research tools – examples; meter sticks, calculators, machines, charts, graphs, computers b) Sources of error – scientists must be careful to avoid errors in data collection and analysis The larger the sample size the more reliably researchers can analyze that variation and evaluate the differences between experimental ad control groups.

5. Drawing conclusions Scientists use data to support, reject or revise the hypothesis being tested.

 

6. When experiments aren’t possible Scientists have to use observations sometimes to test hypothesis

1.1 assessment 1. A. Review what is science B. Explain what kinds of understanding does science contribute about the natural world C. Form an opinion Do you think that scientists will ever run out of things to study? Explain your reasoning. 2. a. Review What are the steps of scientific methodology? b. Explain Why are hypotheses so important to controlled experiments?

Science in context Objectives for 1.2 Explain how scientific attitudes generate new ideas Describe the importance of peer review Explain what a scientific theory is Explain the relationship between science and society

The process of science As the arrows indicate, the different aspects of science are interconnected—making the process of science dynamic, flexible, and unpredictable.

A. Exploration and Discovery: Where ideas come from What scientific attitudes help generate new ideas? 1. Scientific attitudes a) Curiosity b) Skepticism- question existing ideas and hypotheses; refuse to accept explanations without evidence c) open-mindedness- willing to accept different ideas that may not agree with their hypothesis d) creativity -use it to design experiments

Exploration and Discovery Ideas in science can arise in many ways—from simple curiosity or from the need to solve a particular problem. Scientists often begin investigations by making observations, asking questions, talking with colleagues, and reading about previous experiments.

2. Practical problems Ideas for scientific investigations arise from practical problems People living on a strip of land like this one in Murrells Inlet, South Carolina, may face flooding and other problems.

3. The role of technology Scientific discoveries may lead to new technologies. Those technologies help other scientists develop more experiments. Technological advances also have big impacts on daily life.

B. Communicating Results: Reviewing and sharing ideas Why is peer review important? 1. Peer review- scientists publish articles about experiments to be reviewed by anonymous, Independent experts. Publishing peer reviewed articles in scientific journals allows researchers to share and to test and evaluate each other’s work. Peer review does not guarantee that a piece of work is correct, but it does certify that the work meets standards set by the scientific community. 2. Sharing knowledge and new ideas

Applying concepts An advertisement claims that studies of a new sports drink show it boosts energy. You discover that none of the study results have been peer reviewed. What would you tell consumers who are considering buying this product?

Communicating Results Communication is an important part of science. Scientists review and evaluate one another’s work to ensure accuracy. Results from one study may lead to new ideas and further studies.

How do new findings fit into existing scientific understanding How do new findings fit into existing scientific understanding? Perhaps they spark new questions... like... If growth of salt marsh grass is found to be limited by available nitrogen, then is the growth of other plants in the same habitat also limited by nitrogen?

3. Scientific Theories What is a scientific theory? Theory – In science, the word theory applies to a well-tested explanation that unifies a broad range of observations and hypotheses, and that enables scientists to make accurate predictions about new situations.

D. Science and Society What is the relationship between science and society? Using science involves understanding its context in society and its limitations. 1. Science, Ethics, and Morality Science can’t tell us why life exists, what the meaning of life is or how technology and scientific knowledge can be applied 2. Avoiding Bias Bias - particular preference or point of view that is personal, rather than scientific. Science should be objective.

Applying concepts A study shows that a new pesticide is safe for use on food crops. The researcher who conducted the study works for the pesticide company. What potential biases may have affected the study?

Science and society Science both influences society and is influenced by society.

3. Understanding and Using Science Understanding science will help you make complex decisions that also involve cultural customs, values, and ethical standards.

1.2 Assessment Questions 1.a. List the attitudes that lead scientists to explore and discover. b. What does it mean to describe a scientist as skeptical? Why is skepticism an important quality in a scientist? 2. What is peer Review? 3. What is a scientific theory? 4. a. How is the use of science related to its context in society? b. Describe some of the limitations of science.

III. Studying Life A. Characteristics of Living Things What characteristics do all living things share? Biology is the study of life Living things are made up of basic units called cells, are based on a universal genetic code, obtain and use materials and energy, grow and develop, reproduce, respond to their environment, maintain a stable internal environment, and change over time.

Living things: 1. are based on a universal genetic code Living things: 1. are based on a universal genetic code. DNA is the molecule that carries the genetic code that controls how an organism lives, grows and reproduces. 2. grow and develop 3. respond to their environment. Stimulus – a signal to which an organism responds

4. Reproduce sexual reproduction – cells from two parents unite to form the first cell of a new organism asexual reproduction – a single organism is able to produce offspring identical to itself 5. maintain a stable environment. Homeostasis – relatively constant internal physical and chemical conditions that organism maintain

6. obtain and use material and energy. Metabolism - the combination of chemical reactions through which an organism builds up or breaks down materials 7. made up of cells 8. taken as a group, evolve

B. Fields of Biology How do different fields of biology differ in their approach to studying life? Biology includes overlapping fields that use different tools to study life from the level of molecules to the entire planet. 1. Global ecology – activities of living organisms profoundly affect atmosphere and climate and therefore affect other organisms.

2. Biotechnology – scientists are learning how to edit and 2. Biotechnology – scientists are learning how to edit and rewrite genetic code, to correct or replace damaged genes that cause inherited diseases. These issues raise ethical, legal and social questions. 3. Building the tree of life – combining the genetic information with computer technology to organize all living things into a single universal tree of life.

4. Ecology and evolution of infectious diseases – pathogens are 4. Ecology and evolution of infectious diseases – pathogens are dynamic and constantly changing 5. Genomics and Molecular biology – focuses on studies of DNA and other molecules inside cells

C. Performing Biological Investigations How is the metric system important in science? Most scientists use the metric system when collecting data and performing experiments.

1. Scientific measurement- scientists need a common system of measurement because they repeat each others experiments. Metric system – a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10. 2. Safety -

1.3 assessment List the characteristics that define life. A. What are the themes of biology that come up again and again? B. Suppose you discover a new organism. What would you expect to see if you studied it under a microscope? 3. A. Why do scientists use a common system of measurement? B. Suppose two scientists are trying to perform an experiment that involves dangerous chemicals. How might their safety be affected by not using a common measurement?