Chapter 1: The Science of Life

Objectives 1. Recognize some possible benefits from studying biology 2. Summarize the characteristics of living things

Ch. 1 Biology I. What is biology?= the study of life A. Diversity of life 1. Biology = study of all living things and how they interact 2. Organism: anything that posses all of the characteristics of a living thing 3. No species live alone, they all effect one another

B. Seven Characteristics of Living Things: 1.Living things are organized and made of cells  biological molecules -organelles - cells – tissues – organs – organ systems – organism Cells are the basic unit of life

2. Living things have the ability to reproduce and make fertile offspring –Species= group of organisms that can interbreed and produce fertile offspring in nature

3. Living things grow (cell division) and develop (mature) throughout their life 4. Living things respond to their environment –Stimulus: a condition that requires an organism to adjust –Response: reaction to the changed condition (stimulus) 5. Living things maintain homeostasis –Maintain stable internal conditions (temp, blood pressure. breathing etc…)

6. Living things use energy to do work (metabolism) 7. Living things adapt to their environment = EVOLUTION –The strong will survive and populate the area (evolution)

Objectives sec 2 Identify three important themes that help explain the living world. Summarize why evolution is an important theme in biology.

II. Themes in Biology A. Diversity= Variety 1. All living things have unique characteristics that make them different 2. All living things also have similarities that can “tie” them together –Ex: genetic code

B. Domains & Kingdoms of Life –The three domains of life are: Bacteria Archaea Eukarya. –The six kingdoms Archaea Bacteria Protista Fungi, Plantae Animalia.

Phylogenetic Diagram of Living Organisms

C. Interdependence of Organisms 1. Organisms live in interdependent communities and interact with both organisms and the environment. –Ecology = study organisms interactions with environment

Evolution of Life 1. Evolution= descent with modification –The process in which the inherited characteristics within populations change over generations. 2. natural selection: nature “chooses” who survives (fits in best) 3. adaptations = qualities that allow you to survive and reproduce

Objectives sec 3 Outline the main steps in the scientific method. Summarize how observations are used to form hypotheses. List the elements of a controlled experiment. Describe how scientists use data to draw conclusions. Compare a scientific hypothesis and a scientific theory. State how communication in science helps prevent dishonesty and bias.

The scientific method 1. State the problem: pose a question 2. Make observations & inferences –Observation: using your senses to gather information –Data: facts, figures, gathered through observations –Inferences: interpretation of an observation

1. Observe: Is there ever a year in high school when all students are enrolled in physical education? Explain your answer. 2. Infer: Is there a relationship between the number of students enrolled in physical education and their year of high school? Explain your answer. 3. Observe: Can you tell which states in the country have the largest number of students enrolled in physical education? 4. Infer: Based on the graph, can you explain why so few students take physical education in their senior year?

3. Develop a hypothesis a. Possible explanation or educated guess based on your observations 4. Test hypothesis/experiment a. variables: factors that can change an experiment b. independent variable; variable that is changed

–C. dependent variable: factor that changes because of the independent variable –D. controlled experiment: all of the variables remain the same Use this as a comparison

Click below to watch the Visual Concept. Visual Concept Controlled Experiment and Variable

5. Measuring, collecting and interpreting data –Charts and graphs keep the information well organized

6. Drawing conclusions –Summing up what you have learned –State evidence that either supports or refutes the hypothesis –Easy to write as an “if then” statement

7. Communicate = report your results to others! –Others must be able to reproduce your work and get the same results –Share information (especially with health care) to educate others

Scientific Theory vs. Law (principle) 1. Well-tested concept that explains observations 2. Based on many years of experimentation 3. Nothing is 100% correct, but theories have not been proved wrong yet 4. Laws or principles are known to be true (law of gravity)

Objectives sec 4 List the function of each of the major parts of a compound microscope. Compare two kinds of electron microscopes. Describe the importance of having the SI system of measurement.

Section 4. Microscopes A.2 functions – magnify (make bigger) resolution (focus in) B.Compound microscopes have more than one lens and allow you to view living things

C. Scanning Electron Microscope (SEM) – allows the surface of an object to be seen up to 100,000x D. Transmission Electron Microscope – allows the internal parts of an object to be seen up to 200,000x

Units of Measurement Base and Other Units –Scientists use a single, standard system of measurement, called the metric system. The official name of the metric system is Système International d’Unités or SI.

Units of Measurement Base and Other Units –The metric system has seven base units.