THE SCIENCE OF LIVING THINGS

THE SCIENCE OF LIFEModern BiologyCHAPTER 1

1In your notebook, respond to the following questions:

Why do we study Biology?

What is the goal of science?Do now:2The goal of science is to:investigate and understand the natural world.explain events in the natural world.use those explanations to make useful predictions.Science Learning About the WorldScientific Inquiry - Everything that we know in science, especially biology, is the result of combined human effort to understand or improve our understanding of the natural world!WonderingCuriosityAsking questionsThat is the beginning of all scientific studies.

3Section 1-1 unifying themes of biology

4Biology - The Study of LifeBIOLOGY-the study of all living things.EXAMPLES OF SPECIFIC AREAS:Histology-the study cells and tissuesGenetics-the study of how traits are inheritedMolecular biology-how organisms function on the molecular levelEcology-how organisms interact.5Biology - The Study of LifeORGANISMS-living thingsEXAMPLES:PlantsInsectsHumansBacteria

6Biology is unified by certain themes (patterns that connect living things)EvolutionReproduction and InheritanceDevelopmentCell Structure and FunctionMatter, energy and organizationInterdependence of organisms*Science & Society

6 Major Themes of Biology7Evolution-population of organism changes over generations (time).

1. Evolution

8All organisms come from existing organisms.Transfer hereditary information in the form of deoxyribonucleic acid (DNA).Can be:ASEXUAL REPRODUCTION-only one organisms DNA is used. Offspring is identical to parent.EXAMPLE: bacteria dividingSEXUAL REPRODUCTION-DNA from 2 organisms is combined. Offspring is different from both parents and from any other offspringEXAMPLE: humans having a babyEgg and sperm zygote (fertilized egg).

2. Reproduction & Inheritance

9This baby has inherited some traits from its mom and some from its dadit may look similar to one or both of them, but its DNA is a combination of the two!

2. Reproduction & Inheritance

10All organisms are made of cells.UNICELLULAR-made of only one cell (amoeba, paramecium)MULTICELLULAR-made up of many different types of cells working together (tree, spider, shark).DEVELOPMENT-process where a zygote (combined sperm and egg) becomes a mature (adult) individual.

3. Cell structure & function113. Cell structure & function

12The structure (way an organism is put together) is connected to its function (how it works).EXAMPLE:Birds wingHuman handStomachMuscle cell**The Cell is the basic unit of life. All organisms are made of and develop from cells.3. Cell structure & function13The structure (way an organism is put together) is connected to its function (how it works).EXAMPLE:Birds wingHuman handStomachMuscle cell**The Cell is basic unit of life. All organisms are made of and develop from cells.3. Cell structure & function143. Cell structure & function

15Living things must maintain stable internal conditions to survive.Homeostasis- stable level of internal conditions found in all living cells.EXAMPLES:temperaturewater contentfood intake4. Stability & homeostasis

16All organisms obtain, use and transfer energy.ALL energy comes from the SUN.Autotrophs-organisms that can get energy by producing their own food.EXAMPLES: plants and some unicellular organismsHeteroptrophs-organisms that must get energy by eating other organismsEXAMPLES: some unicellular organisms, all animals and fungi5. matter, energy & organization

17Ecology-the study of how organisms interact with each other and with their environment.All organisms need substances (nutrients, water, gases) from their environment.

6. Interdependence of organisms

18Knowledge from science can be used to improve life.Example: polio vaccine, penicillin.

Science & society

19IS IT ALIVEOR IS IT??20In your notebook, respond to the following:Suppose you discovered an unidentified object on your way home from school. How would you determine if it is a living or a nonliving thing?

DO NOW:

21Sect 1-2 the world of biology

22All organisms, no matter how different, have certain characteristics in common THE CHARACTERISTICS OF LIFE !

The characteristics of life

23All living things are composed of cells

1. Made of cells

24All living things are highly organizedOrganized at cellular and molecular level. Cell structures (organelles) carry out specific functions.Multicellular organisms may contain many types of cells, each type carrying out one job (Specialized-carry out one set of functions).

2. organization

25In multicellular organisms, cells and groups of cells (tissues) are organized by their functionCells tissuesTissues organsOrgans systemsSystems ORGANISM

2. organization

26All living things use energyAll organisms use energy to grow and make repairs.Metabolism-all the chemical reactions that take place in a living organism.

3. Energy use

27 All living things respond to their environment Response-reaction to input from the world.May be simple or complex.EXAMPLE: gazelle runs away from a lion.

4. Respond to environment

28All living things grow and developAs cells divide and get larger, the organism becomes bigger.5. growth

29All living things reproduceCreate more of their own species.Essential to the survival of the speciesNOT of the reproducing organism.6. reproduction

30All living things maintain stable internal conditions(Homeostasis) EXAMPLE: water balance, ph, gas exchangebirds feathers fluffing up in cold weather.7. Maintain homeostasis

31Compare an icicle to a carrot. Make a chart that lists the characteristics of life. Decide which of them that each meets and use the chart to decide which is alive and which is not. Explain.Check for understanding

32Section 1-3 scientific methods

33Watch this at HomeHow simple ideas lead to scientific discovery34Do NowRespond to the following in your notebook:

How do we investigate and acquire knowledge in science?35What do you see in this picture?

36The Scientific MethodWhat is it??Scientific Methoda systematic way of developing an answer to a question or problem through experimentation.37The Scientific MethodThe Scientific Method has 6 steps:

Observation (Asking questions & collecting data)Hypothesis (explains their observations and can be tested!!)Experiment (testing your hypothesis)Organizing DataConclusionCommunication

38The Scientific Method

39Step 1 - ObservationUse the 5 senses to perceive objects or events.Asking a questionBased on observations; one or more questions are generated.

40Step 2 Forming a HypothesisOnce a specific question has been asked, a scientist can think about possible answers to the question.Hypothesis-a possible explanation for what was observed that must be able to betested.

May be disproven as new data is collected.If/then statement-often written in this form.Example: If the amount of sunlight is affecting the growth of my plants, then plants receiving more sunlight should grow at a faster rate.

41Step 3 - ExperimentingA test of the hypothesis by gathering data under controlled conditions.Conducting a controlled experiment.Data-observation and measurements gathered during the experiment.Based on a comparison of a control group with an experimental group.

42Step 3 - ExperimentingBoth are identical except for one factor (independent variable).Observations and measurements are taken for a particular factor (dependent variable) in both groups.Driven by/or results from independent variable.

43The Scientific MethodWhat are the parts of an experiment?Control Group- in an experiment, the group is the standard of comparison with the other group, does not receive the experimental factor, the normal group.Experimental Group- in an experiment, group exposed to the experimental factor, but is otherwise IDENTICAL to the control group.

44The Scientific MethodWhat are the parts of an experiment?Independent Variable-the factor deliberately changed by the scientist; the one factor different between the groups.**Independent variable causes a change in what you are measuring the dependent variable**Dependent Variable-the one thing that is measured in the experiment, directly influenced by the independent variable.Outcome variable measured each time the independent variable is changed.

45Step 4 Organizing DataInvolves placing observations and measurements (data) in order.Charts, tables, graphs or maps.

46Step 4 Organizing DataAnalyze dataDetermine if the data has meaningIs the data reliable (trustworthy)?If Yes---run the experiment againand again!If NO---make a new hypothesis and run experiment again.

47Step 5 - ConclusionConclusions are made on the basis of facts, not observationsOften drawn from data gathered from a study or experimentShould support the hypothesisShould be re-testable

48Scientists must share the results of their studies with other scientists (peers)Publish findings in journalsPresent their findings at scientific meetingsScientists must be unbiasedShould not tamper with their dataOnly publish & report tested & proven ideasStep 6 - Communication

49Sharing of information is essential to scientific processSubject to examination and verification by other scientistsAllows scientists to build on the work of othersStep 6 - Communication

50

TheoriesA theory may be formed after many relatedhypotheses have been tested and supported withexperimental evidenceA broad and comprehensive statement of what is thought to be trueSupported by considerable evidenceTies together related hypothesesType:51LawsA Statement of fact that concisely explains an action or group of actionse.g. Law of GravityAccepted to be trueUniversalMay be expressed as a math equatione.g. E=mc2

52Observation: I notice that some plants in my yard are not growing at the same rate. Some plants seem to grow faster than others. The plants that are growing faster seem to be exposed to more sunlight that the other plants.Question: Why are some growing faster?Example : Scientific Method

53Check For Understanding:I love to garden, but always seems to kill the plants. I am especially jealous of my son, Nicholas, because everything he plants grows. This summer I bought a special plant food to see if it will help my plants to grow faster. Question/Observation:Hypothesis (If/then):Parts of the experiment:control group:experimental group:independent variable:dependent variable:constants:

Example : Scientific Method54Respond to the following in your notebook:

What constitutes evidence? What makes a question scientific?Do Now

55Sometimes we need to see thingssmaller than we can see with our eyes.Use a:Microscope-instrument that produces a larger image of an object.WHAT DOES A MICROSCOPE DO?Produces a larger image of an object.Magnification-the amount an objects size is increasedResolution-the power to show details clearlyMicroscopy & Measurement

56Section 1-4 : Microscopy & measurement

57Compound Light MicroscopeSpecimen mounted on aglass slideMust be thinly sliced or very smallPair of lensesOcular lens (eye piece)Objective lens (nose piece)Can be used to study LIVE specimensMagnification determined by multiplying power of both lensesEyepiece 10X times Objective power (20X, 40X)Highest Maximum magnification is around 1000XMicroscopy & Measurement

58Electron MicroscopesTransmission EM (TEM)Uses a beam of electrons to produce an enlarged image of very thinly sliced specimen on screen or photographic plateImage focused by magnetic lenses200,000X magnificationCannot be used to view living specimensMicroscopy & Measurement

59Scanning EM (SEM)3D imageSpecimens not sliced for viewingSurface sprayed with fine metal coatingAlso uses electron beam and fluorescent screen or photographic plates100,000X magnificationCannot be used to view living specimensMicroscopy & Measurement

60Conversions within the metric systemWatch This at Home:

61Scientists use one system of measurements.Called Systeme International dUnites (SI), aka The Metric SystemBase UnitsDescribe what you are measuring.Length-meter (m)Volume-liter (L)Mass-gram (kg)Temperature-Celsius (C)Time-second (s)Microscopy & Measurement62Not everything you measure is 1 meter or 1 gramUS- inch, feet, yard, mile, ounce, pound, tonIn SI, prefixes are added to the base unit (meter, gram, liter).Prefixes are multiples of 10Kilo-k- 1,000Hecta-h-100Deca-da-10Deci-d-0.10Centi-c-0.01Milli-m-0.001Microscopy & Measurement63This makes conversions easier!

1 mile=1760 yards=5280 feet=63,360 inches1km=1,000m=100,000 cmMicroscopy & Measurement

64Mass vs. Weight

Mass-How much matter (particles) you are made of.Weight-How much gravity pulls on you.A quick side note65