Bio 101 Introduction to Biology Janice Lapsansky MWF

Bio 101 Introduction to Biology Janice Lapsansky MWF 8 -8: 50, AH 100 Fall 2007 (no labs this week) Office: Biology 305 Phone: 650 -7337 Email: janice. lapsansky@wwu. edu

Success in Bio 101: • • • Attend class and lab meetings Pre-read Use all of the resources available – print the PPT handouts • • • Form study groups Plan for enough study time Know your preferred learning style(s) Record lectures Check-out a “clicker”

Want an Override to register? 1. E-MAIL the TA (teaching assistant) assigned to the lab you want. 2. Continue to attend lecture. 3. If issued an override, you must register before 5 pm on Friday, Oct. 5 th, or you will be charged $40 late fee by the Registrar.

Learning Objectives 1. 2. 3. 4. 5. 6. 7. Describe the work of biologists and the method they use to create knowledge about living things. Differentiate between inductive and deductive reasoning. Which is used more often in biology? Which of the steps in the scientific process is the most important: observation, hypothesis, or test? Justify your answer. Create a hypothesis and describe its use to answer an important question in science. Compare and contrast the levels of organization in biological systems. Describe the characteristics shared by all living things. Use these characteristics to distinguish one non-living thing (e. g. a virus or a table) from yourself. Describe the classification of all living things according to the 5 -Kingdom classification scheme.

Biology: The Science of Life Why do we study life? How do we study life? -- a matter of scale - size and time -- chemistry & physics -Which ideas & concepts guide biologists? Oldest known fossil of cyanobacteria.

How do you respond to the following statement? “Living things are chemical and physical machines. ” Do you tend to have holistic view of life, or do you see life as a sum of its parts?

Life’s Levels of Organization The world of life shows levels of organization, from the simple to the complex, which extend through: cells (made of? ) tissues & organs organisms populations communities ecosystems the biosphere

Organizing the Diversity of Life Taxonomy p. 8 = the process of naming and classifying organisms Three Domains: Archaea Bacteria Eukarya Five Kingdoms: (see figure on next slide) Carolus Linnaeus What is his claim to fame?

Themes in the Study of Life 1. Levels of organization: The difference between living and non-living is one of degree, not kind. What does this mean? The cell is life’s basic unit of structure and function What is a cell? List one example that illustrates the interdependence of structure and function.

What are some of the main similarities & differences between bacteria and human cells? How is this order maintained, and what does it cost?

Levels of Organization (plant example) p. 4

(animal example) (A biome is a group of ecologicallysimilar communities. )

Themes in the Study of Life 2. Informational Molecules Some biological molecules contain “code” by virtue of the sequence of their building blocks. Name the type of molecule that contains the instructions for maintaining the structure and function of an organism. Name the type of molecule that is made from these instructions. All forms of life use this same code Are there other similarities that unify the diversity of life? Inheritance of traits relies on accurate duplication and transmission of this code to offspring Can organisms change because they “have to” in order to survive in a challenging environment? p. 6

Themes in the Study of Life 3. Emergent Properties Each level of biological organization has emergent properties that result from the interaction between structure and function These emergent properties include the range of characteristics we would use to describe life: metabolism, growth and development, homeostasis, reproduction, and evolutionary adaptation. p. 4

Metabolism All living things depend directly or indirectly on all other living things for survival Briefly describe how an organism changes its biotic environment…. its abiotic environment. Describe the flow of energy and raw materials through the biosphere. p. 6

What does this figure describe? What else “flows” from producers to consumers to decomposers?

p. 7

Growth & Development p. 6 How and why may an organism change over it’s lifespan? Animals often exhibit metamorphosis in their development. Can you explain at least one advantage to this “strategy”?

Homeostasis = the maintenance of a dynamic equilibrium Why does an organism’s internal environment change? Why is a stable internal environment important to an organism’s survival? Describe an example. Most homeostatic mechanisms operate as negative feedback loops. p. 7 Draw the components of a basic negative feedback loop.

Reproduction Which of these groups of organisms have sexual reproduction? Which can reproduce asexually?

Who accurately describes an important observation made by Charles Darwin that was pivotal to the development of his concept of evolution? Populations never produce more offspring than can be supported by the environment Alice Some individuals possess traits that make them more “fit” in their environment Barry Individuals in a population exhibit at least slight differences in their structure and/or function Cal Human skin cells look like bacterial cells from mineral hot springs Dan

Evolutionary Adaptation p. 10 Evolution is the core theme of biology – All living organisms are descended from a single common ancestor • “descent with modification” – Natural selection is one mechanism of evolution • In response to gradual, long-term changes in the environment Evidence indicates that life on Earth first appeared more than 3. 5 billion years ago.

Help Paris with her homework… True or False. Evolution creates adaptations. 1. Individuals w/in species are variable. 2. Some variations are passed on to offspring. 3. More offspring are produced than can survive. 4. Survival and reproduction are not random. Justify your answer.

The Process of Science A human activity that attempts to describe and explain the world – begins with a question/problem – one way to acquire knowledge Can any question be answered by the scientific method? Can science prove “cause-and-effect” between two variables? 2 basic ways to approach a question: • inductive reasoning • deductive reasoning

Inductive Reasoning: generalize from specific observations (Read the “turkey goodness” story on p. 15) When is inductive reasoning used in the scientific process? Deductive Reasoning: propose a model (involving assumptions) that provides a tentative explanation that can be applied to specific situations requires that evidence be collected to test the model and assumptions

Flashlight doesn’t work Observation(s) Why doesn’t it work? Question Hypothesis A Hypothesis B Hypothesis C Batteries are dead Bulb is broken Connectors are dirty Prediction A Prediction B Prediction C Change batteries… Change bulb… Clean connectors… Test experiments, further observations, simulations

• What important skills are critical to your ability to formulate hypotheses? • When is more than one hypothesis appropriate in science? • What is a scientific theory and how is it different from a hypothesis? When you begin to formulate a question, make sure it is answerable by the scientific method. In other words, the topics of scientific investigation must be: 1) well-defined 2) measurable 3) controllable p. 11

Small Group Exercise: An Introduction to Correlation Does smoking cause lung cancer? Does drunk driving cause accidents? Do thin people live longer? You may think you know the answers to some or all of these questions already. On what evidence and/or reasoning do you base your answers? The collection and analysis of data to determine whether two variables are “linked” are important elements in scientific investigations. Finding variables to be linked (i. e. correlated) suggests the possibility of a cause-and-effect relationship. The purpose of this small group exercise is to evaluate information based on the results of scientific research, as reported in a newspaper article. Read the article and answer the questions that follow.

Doing poorly: Study links low income with high blood pressure 1. What two variables are correlated according to the article? 2. Is this proposed as a direct or inverse correlation? Explain. 3. Does either the author or researcher argue that one of the variables causes the other? Explain 4. What other explanations could there be?