Invitation to Biology 1
____________________________________________________________________________________________ INVITATION TO BIOLOGY Chapter Outline 1.1 THE SECRET LIFE OF EARTH 1.2 LIFE IS MORE THAN THE SUM OF ITS PARTS 1.3 HOW LIVING THINGS ARE ALIKE Organisms Require Energy and Nutrients Organisms Sense and Respond to Change Organisms Use DNA 1.4 HOW LIVING THINGS DIFFER 1.5 ORGANIZING INFORMATION ABOUT SPECIES A Rose by Any Other Name. . . 1.6 THE SCIENCE OF NATURE Thinking about Thinking The Scientific Method 1.7 EXAMPLES OF EXPERIMENTS IN BIOLOGY Potato Chips and Stomach Aches Butterflies and Birds 1.8 ANALYZING EXPERIMENTAL RESULTS Sampling Error Bias in Interpreting Results 1.9 THE NATURE OF SCIENCE The Limits of Science 1.10 THE SECRET LIKE OF EARTH (REVISITED) SUMMARY SELF -QUIZ DATA ANALYSIS EXERCISE CRITICAL THINKING Learning Objectives 1.1 Examine why it is important to understand our natural world. 1.2 List the eleven levels of life’s organization. 1.3 Outline the significance of energy and nutrients to organisms. 1.4 Examine how classification helps in understanding biodiversity using examples. 1.5 Examine the importance of taxonomy in the classification of different species. 1.6 Examine the importance of critical thinking in the application of the scientific method. 1.7 Recognize the importance of experimental research to the field of biology using an example. 1.8 Examine how sampling errors occur in scientific experiments and what methods researchers use to combat errors and bias. 1.9 Examine how science works. 1.10 Examine the limits of science. Biology The Unity and Diversity of Life, 14e Cecie Starr Ralph Taggart Christine Evers Lisa Starr (Instructor Manual All Chapters, 100% Original Verified, A+ Grade) Chapter One Key Terms animals archaea atoms bacteria biodiversity biology biosphere cell community consumers control group critical thinking data deductive reasoning dependent variable development DNA ecosystem emergent properties energy eukaryotes experiment experimental group fungus, fungi genus, genera growth homeostasis science hypothesis independent variable inductive reasoning inheritance law of nature model molecules nucleus nutrient organ s organ system s organism photosynthesis plants population prediction probability producer prokaryotes protists reproduction sampling error science scientific method scientific theory species specific epithet statistically significant taxon taxonomy tissue s traits variable Lecture Outline 1.1 The Secret Life of Earth A. Are there any places left on Earth that have not been explored? 1. Yes: a 2005 trip to New Guinea discovered many new plant and animal species . 2. New species, mostly smaller organisms, continue to be discovered every day . B. The more we learn about nature, the more we realize how much more there is to learn . C. This text helps students discover “life,” that is, how orga nisms are constructed, how they live, etc. 1.2 Life Is More Than the Sum of Its Parts A. Pattern in Life’s Organization 1. Biologists examine all aspects of life, from the smallest atom to global communities. 2. Cells are the fundamental building blocks of life. 3. The levels of organization grow in complexity: atoms → molecules → cells → organism . 4. Multicell ular organisms have increasingly complex levels of organization that result in tissues → organs → organ systems → organisms → populations → communities → ecosystems → biosphere. 5. At each successive level of organization , emergent properties can be detected . 1.3 How Living Things Are Alike A. Organisms Require Energy and Nutrients 1. Energy, the capacity to do work, moves through the universe in a series of transfers. 2. Higher levels of organization would cease without energy inputs from the environment. 3. Energy flows from the sun. Invitation to Biology a. Producers (plants and other photosynthetic organisms) make their own food by converting sunlight to usable energy. b. Consumers (animals and decomposers) cannot make food, but use other organisms to obtain their energy and molecular building blocks (carbohydrates, fats, and proteins). 4. Energy flows one way through producers, consum ers, and back to the environment. 5. Energy flow is not 100 percent efficient , as heat (a form of energy) is lost at each transfer stage. B. Organisms Sense and Respond to Change 1. Receptors and the stimuli they receive allow organisms to make controlled responses to heat and cold, harmful substances, and varying food supplies. 2. All organisms undergo homeostasis, a state in which the conditions of the “internal environment” are maintained within tolerable limits. C. Organisms Use DNA 1. Deoxyribonucleic acid, or DNA, is considered the signature molecule of life. a. DNA carries the hereditary instructions that allow organisms to grow and reproduce. 2. Inheritance is the acquisition of traits through the transmission of DNA from parents to offspring. 1.4 How Living Things Differ A. Organisms may vary greatly, which we call Earth’s biodiversity. B. One way animals can be classified is based on whether their DNA is contained in a nucleus. 1. Bacteria and archaea are single -celled organisms with DNA located outside the nucleus. 2. Eukaryotes are organisms with DNA housed inside the nucleus. a. Protists are simple eukaryotes that are often single -celled organisms. b. Fungi are eukaryotes that often act as decomposers. c. Plants are photosynthetic eukaryotes that serve as food for many other organisms. d. Animals are multicellular eukaryotes that act as consumers. 1.5 Organizing Information about Species A. Taxonomy is a system of naming and classifying species. 1. Carolus Linnaeus developed the two -part naming system that is still in use today. a. The first part of the name is the genus. b. The second part of the name is known as the specific epithet. 2. Species are classified into taxa, which are groups of organisms that share a unique set of features. B. A Rose by Any Other Name. . . . 1. Traits can vary and are used to classify organisms. a. Traits may be based on morphology or processes, such as DNA analysis. b. Ernst Mayr developed the biological species approach, which is based on the ability of organisms to produce fertile offspring. 1.6 The Science of Nature A. Thinking about Thinking 1. All scientific research involves critical thinking —judging information before accepting it. 2. Students should avoid accepting information without question, or failing to consider recognized biases, when processing new scientific information. B. How Science Works 1. Common research practices follow a step -by-step approach known as the scientific method . a. Observe an aspect of nature . Chapter One b. Ask a question or state a problem relating to the observation. c. Develop hypotheses (testable explanations) of the observed phenomenon or process. d. Make a prediction of what the outcome would be if the hypothesis were valid (deductive, “if -then” reasoning). e. Test predictions by experiments, models, and observations. f. Assess the results of such tests. g. Report objectively on the tests and conclusions . 1.7 Examples of Experiments in Biology A. Potato Chips and Stomach Aches 1. A Chicago theater was chosen as a “laboratory” to determine if the synthetic fat called Olestra caused gastrointestinal cramps. 2. Both control and experimental groups were random samples of moviegoers who had no idea which fat -impregnated chips they were eating. 3. Later, the moviegoers were called at home to determine the extent of gastrointestinal distress . a. The results: 15.8 percent of people who consumed Olestra had discomfort vs. 17.5 percent that did not consume Olestra. b. As a result of this study, it does not appear that Olestra causes abdominal distress. B. Butterflies and Birds 1. Researchers of peacock butterflies observed two actions. a. When a peacock butterfly rests, it folds its wings so only the dark underside shows . b. W hen a butterfly sees a predator , it repeatedly flicks its paired forewings and hindwings open and closed, a movement that both makes wingspots visible and produces hissing and clicking sounds . 2. Noises when predators approach —may help peacock butterflies avoid predation. 3. The combination of both activities —camouflage at rest and owl -like eyes (wingspots); ion experiments, in which experimenters manipulated the presence of wingspots or the ability to make the clicking and hissing sounds, revealed that birds are indeed deterred by peacock butterfl y sounds, and even more so by wingspots. 1.8 Analyzing Experimental Results A. Sampling Error 1. Sampling errors occur when conclusions inferred from the subset differ from results from the whole population. a. Sampling error s occur most often when sample sizes are small. b. Selecting a larger population subset or repeating the experiment many times may reduce sampling error. B. Bias in Interpreting Results 1. It is often difficult to study the change in a single variable in human populations. a. For example, the participants in the Olestra study also varied in age, gender, health status, etc. 2. Researchers use critical thinking skills to remove bias from their studies. 1.9 The Nature of Science A. When the hypothesis of an experiment is supported via years of collecting evidence, it is called a scientific theory. 1. A scientific theory can be rejected by a single finding or observation. B. A law of nature is an observed phenomenon for which there is no current scientific explanation.
