THE SCIENCE OF LIFE

THE SCIENCE OF LIFEReference:Modern BiologyCHAPTER 1

1Certain themes unify all Biological Sciences.

Living things, no matter how diverse, share common characteristics.BIG IDEA2

Section 1-1 unifying themes of biology

Cell Structure & Function

Stability & Homeostasis

Reproduction & InheritanceEvolutionInterdependence of Organisms

Matter, Energy & OrganizationEach of these themes will be covered in depth and emphasized throughout the course.3Biology - The Study of LifeBIOLOGY-the study of all living things.EXAMPLES of Biological Sciences:Histology-the study cells and tissuesGenetics-the study of how traits are inheritedMicrobiology-the study of microorganismsEcology-how organisms interact with each other and their environment.Bios is the Greek word for life. - Biology includes the study of the microscopic structures of single cells, as well as the global interactions of millions of organisms. A biologist can study a single-celled microscopic algae found in a pond or the interactions between the abundant and diverse organisms that live in the rainforests of the Amazon.4Biology - The Study of LifeORGANISMS-living thingsEXAMPLES:PlantsInsectsHumansBacteria

5Biology is unified by certain themes, or patterns that connect all living things:Cell Structure and FunctionStability & HomeostasisReproduction and InheritanceEvolutionInterdependence of organismsMatter, Energy & Organization6 Major Themes of BiologyBiological themes come into play no matter what organism or interaction is being studied.6All organisms are made of and develop from cells.UNICELLULAR-made of only one cell (amoeba, paramecium)MULTICELLULAR-made up of many different types of cells working together (tree, spider, dog)1. Cell structure & function

DEVELOPMENT-The series of changes in which an organisms undergoes in reaching its final adult form; or from a lower to a higher state of organization. 71. Cell structure & functionUnicellular Each new cell is identical to the parent. All developing organisms are exact clones of their parents.Multicellular Cells become different from each other as they multiply. All developing organisms are a combination of two parents, but are different from them.

DIFFERENTIATION

Cells are the basic unit of life they are small, but highly organized. They contain structures that carry out the cells life processes.There are many different kinds of cells, but all cells share similar features. Similar features surrounded by a membrane and contain genetic material8Cell - One Name, Many Types

All cells, no matter what kind, have similarities, as well as differences.

Certain cell structures determine the function of the cell.Examples:Red Blood Cells carry oxygenPlant cells carry out photosynthesisUnicellular Microorganisms carry out ALL of life processes.

1. Cell structure & function

9All living things must maintain stable internal conditions to survive.Homeostasis- stable level of internal conditions found in all living cells.EXAMPLES:temperaturewater contentfood intake2. Stability & homeostasis

The koala is a specialist. It can only survive within a very specialized environment, specifically where there are certain species of eucalyptus trees. The koala has a limited diet, feeding on the leaves of those trees alone.10All organisms come from existing organisms. They reproduce and transfer their hereditary information to their offspring.2 Types of Reproduction:ASEXUAL REPRODUCTION-heredity information is not combined - only one organisms DNA is used. Offspring are identical to parent.EXAMPLES: bacteria and other unicellular organismsSEXUAL REPRODUCTION- heredity information (DNA)from two organisms from the same species combine. Offspring are different from both parents and from any other offspringEXAMPLE: monkey having a babyEgg and sperm zygote (fertilized egg).3. Reproduction & Inheritance

11Organisms transfer their hereditary information to their offspring in the form of deoxyribonucleic acid (DNA) the book of life.A gene is a short segment of DNA that contains the instructions for a single trait.

vs.

3. Reproduction & Inheritance

At each stage of an organisms development, only some genes are active or expressedFor example your thyroid gland contains thyroid cells that utilizes the gene segment that codes for thyroid hormone so the cell will produce that hormone. A lung cell, on the other hand, will ignore that gene.

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3. Reproduction & Inheritance

This 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!

134. EvolutionPopulations of organisms evolve or change over time.Evolution -population of organism changes over generations (time).

Natural selection is the most important driving force behind evolution. The survival of organisms with favorable traits cause a gradual change in the population over time (descent with modification)144. Evolution

Natural selection is the most important driving force behind evolution. The survival of organisms with favorable traits cause a gradual change in the population over time (descent with modification)15All living organisms interact with other living organisms and their non-living environment.

5. Interdependence of organisms

16The branch of biology concerned with these interactions is called Ecology.Ecology-the study of how organisms interact with each other and with their environment.5. Interdependence of organisms

All organisms need substances (nutrients, water, gases, shelter) from their environment17All living organisms need a constant supply of energy.

How organisms obtain, use and transfer energy is a major topic of study in biology.ALL energy for life on earth comes from the SUN.6. matter, energy & organization

18Autotrophs-organisms that can get energy by producing their own food.EXAMPLES: plants and some unicellular organisms

Heteroptrophs-organisms that must get energy by eating other organismsEXAMPLES: some unicellular organisms, all animals and fungi6. matter, energy & organization

Where sunlight is unavailable, some organisms can make their own food using inorganic material found around them in their environment. They make everything they need using inorganic material such as sulfur and ammonia to produce their own food. Instead of photosynthesis, these organisms perform Chemosynthesis. The life forms that do this are bacteria & some protozoa.

19https://sites.google.com/site/nhsbiologybunch/home/biology/1-unit-the-science-of-life/concept-review-1

Go to the following link and take the Concept Review Quiz 1_1 2021The World of Biology

22In 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:

23All organisms, no matter how different, have certain characteristics in commonTHE CHARACTERISTICS OF LIFE !

The Characteristics of Life

24All living things are composed of cells

1. MADE OF CELLS

25All living things are highly organizedThey are organized at molecular and cellular level. Cell structures (organelles) carry out specific functions.

2. ORGANIZED

DNA & protein structures are highly organized and contribute to their special functions in living organism. 26Cells tissuesTissues organsOrgans systemsSystems ORGANISM

2. ORGANIZED

In Multicellular organisms, different kinds of cells group together to make up more complex structures.together, these structures are organized into an even more complex structure, all interacting to create a single organized living creature. 27

2. ORGANIZED

Whether an organisms is unicellular or multicellular the organization of the organism shows itself in the way an organism is put together as well as the way it operates. Dandelions plants are made up of complex cells which are organized into stems, leaves, roots and flowers. All come together and interact with one another to create a single, orderly living system. For example, Dandelions mature quickly to produce seeds that withstand drought and freezing. 28All living things use energyAll organisms use energy to grow, reproduce and make repairs.Metabolism-all of the chemical processes that take place in a living organism.

3. USE ENERGY

29All Living things maintain stable internal conditions and respond to their environment.Response - reaction to input (stimulus) from the world.May be simple or complex.EXAMPLE: Bird fluffing its feathers to stay warm

4. HOMEOSTASIS

Even single cells work to keep their internal environment stable.All living things maintain stable internal conditions(Homeostasis) EXAMPLE: water balance, pH, gas exchangebirds feathers fluffing up in cold weather (Chickadee)30All living things grow and develop

5. GROW & DEVELOP

Many non-living things grow as well. Keep in mind that living things grow as a result of cell enlargement and cell division.31Growth is the increase in the amount of livingmaterial in an organism.

The series of changes an organism undergoes in reaching its final adult form is called development.

5. GROW & DEVELOP

Metamorphosis - is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, amphibians, molluscs, crustaceans, Cnidarians, echinoderms and tunicates undergo metamorphosis, which is usually accompanied by a change of habitat or behavior.32All living things reproduceCreate more of their own species.Essential to the survival of the speciesNOT of the reproducing organism.

6. REPRODUCTION

33Compare and Contrast:Make a chart that lists the six characteristics of life.Watch the following video clip, IS IT ALIVEOR IS IT??Use the chart to help you determine whether the object is living or non-living. Support your decision.

Do Now

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What is Science?Science is a process that produces a body of knowledge!Science is carried out because people :WonderAre CuriousAsk questionsThat is the beginning of all scientific research.Science Learning About the World

You may think of science as a list of terms

36The goal of science is to:investigate and understand the natural world.explain events in the natural world.use those explanations to make useful predictions.Gain knowledge:Knowledge from science can be used to improve life.Example: polio vaccine, penicillin, genetically enhanced food

Science Learning About the World

37Watch this VideoHow simple ideas lead to scientific discoveryRespond to the video in your notebook.38BIOLOGY AS A SCIENCE

Scientists study and collect information about organisms, such as physical characteristics, what they eat, how they reproduce and how they interact with other living things and their environment. The naturalists is the photograph is banding individual falcons for further study. The data collected from this band can be added to the body of knowledge that scientists throughout the world have collected on falcons.39Methods of Science

There are methods most scientists follow as they conduct their investigations. Scientific inquiry involves asking a question and using a guided approach to get an answer.There are many questions in Biology that scientists have studied and continue to study.How do spiders make webs?What are viruses?How do birds fly?Why do bears hibernate?Why do birds migrate?How does DNA store genetic information?Scientific 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!

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Methods of ScienceHave you ever tried to figure out what an object in a closed box might be. As you manipulate the box, you are making observations about it, and based on your prior knowledge and experience, were ruling out certain items and leaving open other possibilities. Finally you narrow your choices further and make an educated guess about what is in the box. You used a guided approach, a method or series of steps to arrive at your conclusion. What ever they study, scientists use certain methods or steps to obtain knowledge as well.41

Methods of Science42What methods do scientists use to learn about the natural world?Scientific Method: a guided approach, or series of steps to arrive at an answer to a question or problem through some type of investigation or experimentation.

The Scientific MethodThere is really no fixed way to arrive at answers or explanations to questions, but following a method or a series of steps helps keep the investigation organized. 43The Scientific Method has approximately 6 steps:

Observationasking questionsCollecting dataHypothesis (explains their observations and can be tested!!)Experiment (testing your hypothesis)Collecting, Organizing & Analyzing DataConclusionCommunication

The Scientific Method

Remember science is carried out because people are curiousunderstanding the scientific method will help to answer questions you may have in your own scientific investigations or in your own life!I say approximately, because theses steps do not always follow a precise order and scientists may go back and forth many times between many steps to solve a problem.44Step 1 - ObservationUse the 5 senses to perceive objects or events.Asking a questionBased on observations; one or more questions are generated.

45Step 2 Forming a HypothesisHypothesis-a possible explanation for what was observed and why it should come true . it must be able to be testedIf/then statement-often written in this form.Example: If giving tomato plants Tomato Grow plant food increases the size of the tomatoes a plant produces, then tomato plants feed Tomato Grow may produce larger tomatoes

A hypothesis is an educated guess coupled with an explanation for why that guess should come true.Once a specific question has been asked, a scientist can think about possible answers to the question.46Step 3 - ExperimentingMost experiments in Biology are controlled experimentsperformed to test your hypothesis (confirm or disprove it)Based on a comparison of a control group with an experimental group.Used to gather data under controlled conditions.Data-bits of information gathered during the experiment.

Only when you test your hypothesis can you be certain whether or not you hypothesis the explanation of your observations, is realistic. 47All factors in the control group and the experimental group are identical except for one:independent variablewhat is being testedDuring the experiment, observations and measurements are taken from both groups, looking specifically at another factor or variable:dependent variabledependent because it is driven by/or results from the independent variable.

Step 3 - Experimenting

48To have a controlled experiment, two groups must be tested:Control Group- the group where all the variables remain constant the "normal groupExperimental Group- the group exposed to the experimental factor (independent variable what is being tested), but is otherwise IDENTICAL to the control group.

Step 3 - Experimenting

49Variables:Independent Variable-the factor deliberately changed by the scientist; the one factor that is different between the groups. In a controlled experiment, only the independent variable changes. **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.

Step 3 - ExperimentingA variable is any part of an experiment that can be controlled or changed.50For example, if we were setting up an experiment to test our hypothesis about Tomato Grow plant food, we would set up the experiment using two groups of identical tomato plants. One group, our experimental group would receive the food, while the other group, the control group would not. All other variables would remain constant. The plant food would be considered the independent variable, and only given to the experimental group. In this case, the size of the tomatoes would be the dependent variable, as this factor is dependent upon the manipulation of the independent variable. What factors must remain the same in both groups to ensure that the results you observe are due to changes in the variable being tested? ~ FYI ~

Type and number of plants, amount of water given, the temperature of the environment, amount of sunlight the plants receive, etc. 51If you said one or more of the following, you are correct!Type and number of plantsamount of water giventhe temperature of the environmentamount of sunlight the plants receiveThe pH of the soiletc. ~ FYI ~

Control GroupExperimental Group

Tomato GrowpH 7pH 7Type and number of plants, amount of water given, the temperature of the environment, amount of sunlight the plants receive, etc. 52Step 4 Organizing DataOrganizing:Involves placing observations and measurements (data) in order.Charts, tables, graphs or maps.

53Step 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.

The goal of data analysis is to determine if there is a relationship between the independent and dependent variables.54Step 5 - ConclusionA conclusion is a summary of the experiment's results, and how those results match up to your hypothesis.Often drawn from data gathered from a study or experimentShould support the hypothesisShould be re-testable

Control GroupExperimental Group

Tomato GrowpH 7

pH 7In short, conclusions are written to answer the original testable question proposed at the beginning of the investigation. They also explain how the student used science process to develop an accurate answer.55Scientists share the results of their studies with other scientists (peers). HOW?Publish findings in journalsPresent their findings at scientific meetingsScientists must be unbiasedShould not tamper with their dataOnly publish & report tested & proven ideas that can be re-tested & produce the sameresults.Step 6 - Communication

To be acceptable and useful to other scientists, the results reported must be - free from all favoritism 56Sharing of information is essential to scientific processSubject to examination and verification by other scientistsAllows scientists to build on the work of othersStep 6 - Communication

57The Scientific Method

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Hypothesis Theory LawNo hypothesis, or explanation in science is really ever final.

Science is an ongoing process which is constantly revised and improved as new evidence is found.

But many hypotheses have held up over time.

A Hypothesis that has stood the test of time (even with minor revisions) led to theoriesThe Big Bang Theory how the universe was created, is a theory that is constantly under revision. With the constant improvements in technology (telescopes, shuttles, observatories), scientists are constantly uncovering new information the quest for knowledge to understand the universe will lead us to new information

59Hypothesis Theory LawA THEORY:formed after a hypothesis has been tested over and over and supported by considerable experimental evidenceIs a broad and comprehensive explanation of observationswhat is thought to be trueSubject to revision

Occasionally discoveries are made that are so profound that they do require that we discard the old theory, and start from scratch to develop a new one that fits the new evidence as well as the old. We once thought that the earth was the center of the universe - In the early 20th century, however, the discovery of other galaxies and the development of the Big Bang theory led to the development of models of the Universe which lacks a central point.

**Einstein's theory of general relativity changed our understanding of the universe.

60Hypothesis Theory LawFor Example: Charles Darwins Theory of Evolution

The naturalists, Charles Darwin set sail on a ship around the Galapagos Islands. He observed something that sparked his interest and curiosity and decided to collect some data. After careful analysis of his data, he proposed a hypothesis, that may have read something like - "Individuals best adapted to their environments are more likely to survive and reproduce, thus those useful adaptive traits would be passed on to the next generation and over time lead to evolution. Charles Darwins explanation of how evolution occurs through natural selection is known as a theory because it is backed by substantial evidence and has stood the test of time.

61Hypothesis Theory LawHypotheses and Theories are explanations of observations.On the other hand, LAWS are statements about events that always occur in nature.A LAW doesnt explain why something happens, it just merely states that it does happenAccepted to be trueUniversalMay be expressed as a math equatione.g. E=mc2Scientists use laws to explain theories

For example you know that gravity will always cause an apple to fall to the ground below once it is separated from its tree branch. This observation and others like it about falling objects can be stated as Newtons Law of Gravitation. This law does not explain why it happens, it just says that it does.62https://sites.google.com/site/nhsbiologybunch/home/biology/1-unit-the-science-of-life/concept-review-1_2

Go to the following link and take the Concept Review Quiz #1_2 63Microscopes:Sometimes we need to see thingssmaller than we can see with our eyes.WHAT DOES A MICROSCOPE DO?Produces a larger image of an object. Uses a glass lens and a beam of light.Magnification-the amount an objects size is increasedResolution-the power to show details clearlyMicroscopes vary in powers of magnification and resolution.

Tools of the trade65Compound 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 (10X, 20X, 40X)Highest Maximum magnification is around 1000X

Light Microscopes66Light Microscopes

To see small organisms and cells, biologists usually use a compound light microscope. This will be the type of microscope we will be using in biology class.67Transmission Electron Microscope (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 specimensElectron microscopes

For greater magnification and resolution, biologist use electron microscopes. These microscopes can magnify objects hundreds of thousands of times and provide much greater detail. Giardia Lamblia - protozoa 68Scanning Electron Microscope (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 specimensElectron microscopes

Another type of electron microscope, the SEM, has a lower magnification, but produces a cool, 3-D image. 69The International System of Measurement, or SI is the one system of measurements scientists use.Named after the French Systeme International dUnites and formerly known as: The Metric SystemTools of the trade

Recall that scientists communicate the results of their research to other scientists. The work of every scientists is subject to examination and verification by other scientists. Imagine the difficulty they would have interpreting data if several different types of measurements were used. To prevent errors and confusion, scientists worldwide use a universal system of measurements.70The Metric SystemMajor advantages:It is a decimal system (based on 10s, multiples or 10s or fractions of 10sEasy to convert between prefixesKiloDeciCentiMillimicroUses Base Units - Describe what you are measuring.Length-meter (m)Volume-liter (L)Mass-gram (kg)Temperature-Celsius (C)Time-second (s)Tools of the trade

71Conversions within the metric systemTools of the trade

72US- 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-0.001Tools of the trade

73The SI System makes conversions easier!1 mile=1760 yards=5280 feet= 63,360 inches1km=1,000m=100,000 cm

Tools of the trade74Mass vs. WeightMass-How much matter (particles) you are made of.Weight-How much gravity pulls on you.A quick side note

75One mL of water has a mass of 1gram. Suppose you had a cylinder marked off with 1 mL lines. How could you determine the mass of a small plastic toy dinosaur using such a cylinder? Thinking Critically

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