The Study Of Life Chapter 1

Do Now: If a scientist hypothesizes that a vitamin could extend a person’s life-expectancy, then: 1) What is an experiment that can be made to test this hypothesis? 2) What would be the independent variable? Dependent variable? 3) Give one example each of qualitative and quantitative data that can be collected in this experiment

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1.1 Introduction to Biology MAIN IDEA: All living things share the characteristics of life.

The Science of Life Biology = the science of life 1.Study the origins and history of life and once-living things (evolution, cell theory) 2.Study the structures of living things (atoms, cells, body systems) 3.Study how living things interact (ecology) 4.Study how living things function (energy, respiration, photosynthesis)

What do biologists do? (Don’t copy) Study the diversity of life –Classification of species –Jane Goodall’s study of chimp behavior Research diseases –Find causes, cures, and treatments –Mary-Claire King is focused on finding the genetic cause of breast cancer Develop technologies –technology – use of science knowledge to meet human needs

What biologists do cont’d (Don’t copy) Improve agriculture –Genetically engineered crops –Genetically altered livestock –Organic pesticides Preserve the environment –Protect species to prevent extinction –Reproductive strategies –Deal with issues of waste, pollution, global warming, etc.

The Characteristics of Life How do we know something is, or once was, alive? All organisms share the same characteristics.

1. All organisms are made of one or more cells. Cell – basic unit of structure and function in all living things Can be unicellular (one cell) Can be multicellular (more than one cell)

2. All organisms display organization. Arranged in an orderly way Unicelled organisms – structures or sections within cells that have certain functions Multicelled organisms – specialized cells  tissues  organs  organ systems  organism

3. All organisms grow and develop. Growth – addition of mass (cells, structures) –Ex: A flower stem becomes longer. Development – changes during an organism’s lifetime –Ex: A seed changes into a seedling plant.

4. All organisms reproduce. Reproduction occurs among members of the same species. Not necessary for the individual organism’s survival, but instead for the continuation of the species

5. All organisms respond to stimuli. Anything that is part of an organism’s internal or external environment is a stimulus. A reaction to it is a response. Ex: A door slams, and you turn your head toward the sound. Label stimulus or response: A fly bites you, and you swat at it. A plant grows toward the sun.

6. All organisms require energy. From food Some organisms like plants (producers) make their own food using sunlight (photosynthesis) or chemicals (chemosynthesis). Organisms that can not make their own food (consumers) eat other organisms. Energy  growth, development, performing life functions

7. All organisms maintain homeostasis. Balance within an organism by regulating internal conditions If something happens within or to an organism to upset its normal state, processes start that will restore its balanced state. Ex: -Hibernation –A panting dog –When you get a fever…

8. Organisms develop adaptations that evolve over time. Inherited characteristics Help the survival of a species in changing conditions Do not occur overnight or to an individual Ex: camouflage, insect immunity to pesticides

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1.2 The Nature of Science MAIN IDEA: Science is a process based on inquiry that seeks to develop explanations.

Definitions and Word Origins Science – study of our natural world Inquiry – seeking explanations; based on unbiased observation and experimentation Pseudoscience – “fake” science; areas of “study” that have no real basis in science

Science relies on evidence. Observations, data, experiments, etc. Theory – idea with a LOT of evidence in support of it; many observations and experiments with the same results –studied by MANY different people –ex: Big Bang Theory, evolution Pseudoscience – –no evidence, data, or facts support it; –Ex: astrology, palm reading

Science challenges accepted ideas and questions results. Scientists welcome new ideas; findings Scientists often debate ideas Scientists look for accurate explanations (if something new is discovered that contradicts a known idea, it will be researched further) Pseudoscience – will disregard ideas that go against what they think is true.

Science tests claims. Ideas are researched thoroughly according to specific procedures. Experiments can be repeated by others, and can be retested for accuracy. Pseudoscience – no research or experimental procedures

Science undergoes peer review. Conferences and meetings are held so scientists can review each others’ work. Scientists evaluate each other for accuracy. Pseudoscience? NO!

Science uses the metric system. Same system all over the world, so consistent SI = International System of Units Based on powers of 10, so easier to do calculations Basic units: Length = meter, mass = kilogram, volume = liter, time = second

Science in Everyday Life Jobs useful to society: –Doctors, nurses, pharmaceutical employees, forensics lab workers, environmentalists, genetic counselors…..

EVERYONE should have a sense of… Science literacy – ability to understand issues of science –Issues in daily life – cloning, stem cell research, AIDS research, drugs/alcohol… Ethics – moral values on certain issues

1.3 Methods of Science MAIN IDEA: Biologists use specific methods when conducting research.

Ask a Question Inquiry begins with an observation. Observations may pose questions Questions must be testable

Form a Hypothesis Educated guess Testable explanation of the question Testable or Not? Catherine has seizures due to a lack of sleep. Birds telepathically send each other signals to each other so they can fly in patterns.

Collect Data Information collected from observations Qualitative and quantitative Gathered through controlled experiments or investigations Data organized in charts, tables, lists, etc.; labeled and clear

Controlled Experiments A control group in an experiment is a group used for comparison. The experimental group is the group exposed to the factor being tested.

Experimental Design Independent variable—only one factor in a controlled experiment can change at a time Dependent variable—results from or depends on changes to the independent variable Constant – factor that does not change

Analyze Data Organization of data, calculations Graphs make patterns easier to see Conclusions are drawn from the interpretation of the data Determine if results support hypothesis or not

Report Conclusions Research may be published in journals, magazines, etc. Reviewers and other scientists determine if findings are valid

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