I. Chapter 1: Biology: The Science of Life

Chapter 1: The Study of Life

1Introduction to Biology Objectives for section 1:Define BiologyIdentify possible benefits from studying biologySummarize the characteristics of living things

2The Science of BiologyBiology: The science of life(the study of Life and living organisms)Biology gives us an organized way of studying living things how they interact and function - their origins and history; - develop concepts, principles and theories that allow people to understand their environment. 3What Biologists DoStudy the diversity of lifeResearch diseasesDevelop technologiesImprove agriculturePreserve the environment(Basically they study problems and propose solutions)

4Characteristics of LifeAn organism is anything that has or once had all of these characteristics:

Living things are made of one or more cells

Unicellular -- one-celled (bacteria, protists)Multicellular -- many-celled (humans, plants)

Cells are the basic units of structure and function in all living things.

5Characteristics of Life2) Living things display organizationspecialized parts perform particular functions, like in a factory

celltissueorganorgan systemorganism

6Characteristics of Life

3.All living things grow and develop

growth an ability to increase in size; either by increasing cell size or by adding on other cells - increase in amount of living material, forming new structures

development: all change during life of an organism

7Characteristics of Life4) Living things Reproducereproduction; production of offspringnecessary for the continuation of a speciesOffspring are not identical to the parent (mutations)Change over time (evolution)species - a group of similar looking organisms that can interbreed successfully (fertile)

8Characteristics of living things 5) Living things adjust to their environmentenvironment: living things interface with surroundings

9stimulus: condition in environment which requires an organism to adjust

response: reaction to a stimulus

adaptation: structure, behavior, or internal process enables an organism to respond to stimuli and better survive (are inherited)

6. Living things require energy.

a. Energy: the ability to do work or make things move;1. powers life, homeostasis, movement, growth, reproduction, bioluminescense2. flows through communities (one way)

b. Organisms either make food for themselves (Producers = plants) or have to find and eat food for energy (Consumers = animals)

11 7. Living things maintain homeostasis: regulation of an animals internal environment to maintain conditions suitable to their environmentexamples:Regulate blood sugar levelsRegulate calcium levels in bloodstreamRegulate body temperature

(energy is important here!)

128. Living things have adaptations that evolve over timeCertain features make them better able to survive and reproduce.Adaptations are any inherited characteristic that results from evolution example: drip tips on the leaves of rainforest trees.evolution: gradual change in the characteristics of species over time

13How do you know if an organism is living?Some living things do not display all 8 of the characteristics of lifeCertain bacteria and fungi do not seem to respond to their environmentMules (hybrid of donkey + horse) cannot reproduce, they do not produce viable germ cells. a sterile mule cannot pass on its genes, even if the genes are well adapted. Some individuals never develop to full term and never survive outside of the mothers womb. Furthermore, some offspring are able to pass on their genes, but over the course of multiple generations, in a small population, mutations begin to accumulate and second or third generations are not able to pass on their genes, ending the line of descent.

The Nature of ScienceSection Objectives:Explain the characteristics of scienceCompare something that is scientific with something that is pseudoscientificDescribe the importance of the metric system and SI15What is science?A body of knowledge based on the study of nature.The essential characteristic is scientific inquiry, which can be both a creative process as well as rooted in unbiased observations and experimentation.

Science relies on evidenceWe combine what we already know with consistent evidence gathered from MANY observations and experimentsTheory: - different from what common folk say. An explanation of natural phenomenon that is supported by a large body of scientific evidence obtained from many different experiments and observations over time

Examples:CELL THEORYThis theory says that new cells are formed from other existing cells, and that the cell is a fundamental unit of structure, function and organization in all living organisms.THEORY OF EVOLUTIONThe change in groups of living things over time. Evolution is the process of inheritable differences becoming more common or rare within large groups (populations) of organisms.based on countless experiments and observationshave extensive supporting evidence- allows scientists to predict new facts & relationships

Have you ever read your horoscope in the newspaper?How was it determined?Was it based on sound scientific methodsAstrology is PSEUDOSCIENCE!

Pseudoscience:Areas of study that try to imitate scienceOften driven by cultural or commercial goalsThey do NOT provide science-based explanations about the natural worldExamples: astrology, horoscopes, psychic readings, tarot cards, face reading (Physiognomy), head reading (Phrenology), palmistry.

Expands scientific knowledgeA constant re-evaluation of what is knownThis often leads to new infoNearly every new finding leads to further questioning and research(with pseudoscience, little research is done new questions or research is NOT WELCOMED)Challenges accepted theoriesDebate is welcomedConferences and meetingsDisagreements occur, lead to additional experimentation

Scientists challenge report of one Argentine ant supercolony flooding California

A team of California scientists made headlines four years ago when it reported finding one of the largest insect colonies in the world -- a 600-mile-long subterranean network of Argentine ants stretching from Northern California to the Mexican border. According to the researchers, this "supercolony" is made up of billions of closely related workers -- all direct descendants of a small group of Argentine ants that were accidentally introduced into California more than a century ago.

Graduate student Nicole Heller, left, and biological sciences Professor Deborah Gordon discussed the Jasper Ridge project in Gordon's office. The project analyzed the DNA from ants in the biological preserve and found obvious genetic differences among some of them, suggesting that the ants came from different colonies. Photo: L.A. Cicero

Questions resultsAny observations or data that are not consistent with current scientific understanding are of interestThese lead to further investigationExample: bats used to be grouped with birds due to wings, but later were found more related to mammalian limbs.(pseudoscience discards or ignores observations that are inconsistent with beliefs)

Tests claimsScience-based claims are based upon a large amount of data and observationsThis data is from unbiased investigations and carefully controlled experimentation.Conclusions are reached from the evidence,(pseudoscience makes claims that cannot be tested, mix fact and opinion.Undergoes peer reviewWork is reviewed before it is made public.Review is done by scientists in the same field or who are conducting similar researchThey evaluate the procedures used and the results

Uses metric systemA system that has units with divisions that are all powers of 10.Unit standard were established in 1960Called SI, or International System of UnitsMeterGramLiterSecond

LengthMassVolumeTimeScience LiteracyForensics = study that applies science to matters of legal interestLiteracyIt is important that you are able to understand science and its process with reasoning and thinking skills.

Ethics = the study of what is right or wrong- science ethical issues affect politics, moral, social - once research is done it is people of society make a decision

Section 1.3: observation Methods of ScienceDescribe the difference between an and an inferenceDifferentiate among control, independent variable, and dependent variableIdentify the scientific methods a biologist uses for research1. Ask a questionObservation = a direct method of gathering info about a natural phenomenon in an orderly way.Inferences = combining what you already know with what you have learned to begin making logical conclusions.(an assumption based upon prior experiences)

Ex: when we see smoke, we infer fire

30Observation

Observation: when studying something describe only facts that you can see, touch, smell and hear. You are not making any guesses. THIS IS NOT AN OPINION!!

Ohh This liquid is green and it is leaking from a brown can. I also smell it.Inference

Inference: using your observations to make a guess about an object or an outcomeTHIS CAN BE A SCIENTIFIC OPINION

Based on my observations, I think that this can is old and is leaking a toxic substance.

Scientific Methods:A series of problem-solving procedures that might include: observationsforming a hypothesisExperimentingGathering and analyzing dataDrawing conclusions

Important to noteThis is the way scientific method is usually shown on diagrams or reported in journalsThis is not how science is actually conducted.Science often proceeds in a cyclical manner with one question raising another and one observation and one experimentIt is not always linear.

2. Form a hypothesisHypothesis: testable explanation for a question, problem, or situation. - Scientists are able to hypothesize by making inferences using their background experience, reading, lab work, imagination, logic, curiosity

Serendipity: the occurrence of accidental or unexpected, but fortunate results scientists who made breakthroughs that they were not even looking for

353. Collect the Data:Experiment: to investigate a phenomenon in a controlled setting to test a hypothesis.

Controlled experiments = have:1) a control group a group used for comparison, do not have the experimental variable2) an experimental group the group exposed to the factor that is being tested

36Collect the Data:Experimental design:independent variable the tested factor, it might affect the outcome of the experiment, what is being manipulated or changeddependent variable what is measured, this results from or depends on the changes made to the independent variable

constant a factor that remains fixed (also called control factor)37In summary:Independent variables answer the question "What do I change?Dependent variables answer the question "What do I observe?Controlled variables answer the question "What do I keep the same?Constant variables (control factors) answer the question "What uninteresting variables might influence the effect of the IV on the DV?"38Collect the Data: Data GatheringData = information gained from observations, many experiments use both:Quantitative = numerical data that is easy to analyze statistically (averages, graphs)measurements of time, temp.,length, mass, area, volume, density, etcQualitative = descriptions from 5 senses, give a more in depth and rich description(sometimes is the only data you can get)39Collect the Data:Investigations what we call it when the procedure involves observation and collection of data rather than controlled manipulation of variables (this is not using a control group) Examples: using computers to model natural behavior of organisms & systemsdiscovering and identifying new species404. Analyze the Data:Has my hypothesis been supported?Are more data needed?Are different procedures needed?

Display data in graph or table, this helps to look for patterns or trendsMeetings are held with other biologists to examine for avoiding bias, repeating their trials, and if sample size is large enoughYou also learn from an unsupported hypothesis415. Report Conclusions:Findings/conclusions are reported in scientific journalsFirst is peer reviewed forOriginalityCompetence of scientific method usedAccuracyThen is published for review by public and other scientists(ex: journal of the american medical association)

426. Student Scientific Inquiry:You will have some opportunities to design your own experimentsLab safety there are specific lab safety symbols to help alert you to specific dangers.Make sure you are aware of all lab safety equipment and how to use it

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