AM ): 9:00-11:10 AM

Transcription

1 Biology 1

2 Dr. Rana Tayyar Ø Lecture Monday through Thursday: 11:30 AM 1:40 PM MTSC Room 401 Ø Lab MTSC Room 303 Monday-Thursday AM (Section 41137): 9:00-11:10 AM Monday-Thursday PM (Section 41139): 2:00-4:10 PM Ø Office hours By appointment only

3 Syllabus

4 Ø Objectives of the course Syllabus Ø Grading Ø Exam policies Ø Classroom policies Ø Attendance: Mandatory

5 Succeeding In This Class Ø Take your school work seriously Ø Come to class prepared Ø Attend all lectures Ø Be an active participant

6 Succeeding In This Class Ø Allow some biology time every day Ø Read your notes and rewrite them (within 24 hours is best) Ø Please read the textbook Ø Prepare flash cards Ø Form study groups Ø Discuss any questions with me Ø Come to office hours Ø Tutorial Services: MLK Bldg., Room 232

7 Invitation to Biology

8 Biology Ø Bios = life (from Greek) Ø -logy/-ology = scientific study of a subject Ø Biology = scientific study of life

9 The word science is derived from a Latin word scire meaning to know Science: The systematic study of the observable world and how it works Critical thinking is a big part of science judging information before accepting it

10 Scientific Method Process consisting of a series of steps used to answer questions Ø Is not a rigid procedure Ø Based on evidence to logically solve problems and answer questions

11 Steps of the Scientific Method

12 Hypothesis: testable explanation of a natural phenomenon Prediction: statement, based on a hypothesis, about a condition that should exist if the hypothesis is correct

13 Experiment: test designed to support or falsify a prediction Variable: a characteristic or event that differs among individuals or over time Independent variable: condition or treatment controlled by the experimenter Dependent variable: observed result that is influenced by the independent variable

14 Experimental group: receive a certain treatment or have certain characteristics Control group: identical to an experimental group, but without exposure to the independent variable Sample size and replications

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16 Butterflies and Birds Ø Researchers investigated whether certain peacock butterfly behaviors defend them against predatory birds

17 Initial observations: When a peacock butterfly rests, it folds its wings, so only the dark underside shows When a butterfly sees a predator approaching, it flicks its wings open, producing a hissing sound and a series of clicks

18 Ø First hypothesis: wing-flicking exposes brilliant spots that resemble owl eyes Ø Second hypothesis: hissing and clicking sounds may be an additional defense that deters predatory birds

19 Ø Experimental design: Ø Paint the wing spots of some butterflies black Ø Remove sound-making wing part of others Ø Place butterfly into cage with a hungry blue tit Ø Observe for 30 minutes

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21 Ø Conclusions: Ø The test results supported the hypotheses Ø Predatory birds are indeed deterred by peacock butterfly sounds, and even more so by wing spots

22 Inductive reasoning: drawing a conclusion based on many specific observations Deductive reasoning: using a general idea to make a conclusion about a specific case

23 More Terms relating to scientific inquiries Sampling error Probability Statistically significant Scientific Theory Law of nature

24 Observations Question Hypothesis # 1: Dead batteries Hypothesis # 2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test prediction Test falsifies hypothesis Test does not falsify hypothesis

25 Limitations of Science Science addresses only testable ideas about observable events and processes It does not address anything untestable, such as beliefs and opinions

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27 Forms of Life Share Common Properties Ø Order Ø Use of DNA as hereditary material during reproduction Ø Growth and development Ø Energy Processing Ø Response to stimuli Ø Homeostasis Ø Evolutionary adaptation

28 Order Living organisms are both complex and organized

29 A Closer Look at Biological Organization Life organization extends from the microscopic scale of atoms and molecules to the global scale of the biosphere

30 A Hierarchy of Biological Organization Ø Atom Ø Molecule/ Biological Molecules Ø Organelle/Cell* Cells are the fundamental units of life Ø Tissue Ø Organ

31 Ø Organ system Ø Organism (Beyond the level of organisms) Ø Population Ø Community Ø Ecosystem* Producers Consumers Decomposers Physical environment Ø Biosphere

32 Emergent Properties An organism is a living whole greater than the sum of its parts New properties that arise in each step upward in the hierarchy of life as a result of interactions between components and proper arrangement of components

33 Energy Processing 1) Why do organisms need energy? Ø Power activities and chemical reactions 2) How do organisms obtain energy? Ø Producers Ø Consumers

34 producer acquiring energy and nutrients from the environment consumer acquiring energy and nutrients by eating a producer

35 ENERGY IN SUNLIGHT 3 Producers harvest energy from the environment. Some of that energy flows from producers to consumers. PRODUCERS plants and other self-feeding organisms 4 Nutrients that get incorporated into the cells of producers and consumers are eventually released back into the environment (by decomposition, for example). Producers then take up some of the released nutrients. CONSUMERS animals, most fungi, many protists, bacteria 5 All of the energy that enters the world of life eventually flows out of it, mainly as heat released back to the environment.

36 Cycling of chemicals from the atmosphere and soil through producers, consumers and decomposers back to the environment Energy flow: Sunlight Consumers Producers

37 Response to Environment Response to a stimulus

38 Homeostasis Living organisms have the ability to maintain a stable internal body environment even in the face of a fluctuating external environment

39 Living Organisms Use DNA Ø DNA (deoxyribonucleic acid) carries hereditary information that guides: Ø Development: multistep process by which the first cell of a new multicelled organism gives rise to an adult Ø Growth: increase in the number, size, and volume of cells Ø Reproduction: processes by which individuals produce offspring

40 Ø Inheritance: transmission of DNA to offspring Ø All organisms inherit their DNA from one or two parents Ø DNA is the basis of similarities in form and function among organisms: All forms of life use the same genetic code to translate the information stored in DNA into proteins Ø Small variations in DNA give rise to differences among individuals and among types of organisms

41 The Diversity of Life Taxonomy (Carolus Linnaeus) Science that deals with the identification and the classification of living organisms

42 Ø Domain Ø Kingdom Ø Phylum Ø Class Ø Order Ø Family Ø Genus Ø species Taxonomic Classification

43 Species: unique type of organism Biological species concept Trait: an observable characteristic of an organism or species (morphological, molecular) Taxon: group of organisms that share a unique set of traits

44 The Three Domains The diversity of life can be arranged into three domains: Ø Archaea Ø Bacteria Ø Eukarya

45 Bacteria Archaea Protists Plants Fungi Animals Kingdoms Bacteria Archaea Eukarya Domains

46 Domain Archaea Archaea are prokaryotes that often live in Earth s extreme environments

47 Domain Bacteria Bacteria are the most diverse and widespread prokaryotes

48 Domain Eukarya All members have eukaryotic cells Ø Protists Ø Fungi

49 Ø Plants Ø Animals