Biology: The Study of Life

I. Science means ‘to know’ (in Latin)A. Science is:A body of knowledge A process to learn about the worldB. Biology is:Study of LifeBiologists study the diversity of Life

Characteristics of Living Things:

1-Living things are made up of cells2-Living things reproduce (not

essential for survival but essential for continuation of species)

species = group of organisms that can interbreed and produce fertile offspring

3-Living things changegrowth and development

4-Living things adjust to their surroundings (stimulus / response interactions)

5-Maintain homeostasis (balance internal condition)

6-Living things adapt and evolve 7-All Living things must get and

use energy8-Have a DNA genome

Living Organisms possess ALL of the characteristics of life

So, What Is The difference:

Homeo…. What???Homeostasis: Process by which organisms maintain constant and stable internal conditions. (temperature, blood glucose levels, hormone levels)

Your body works like the furnace and thermostat in

your home. The negative feedback loops run until they get to the proper level, like the temperature setting of the thermostat and then stops until they need to be adjusted again.

Observation: Using your senses to gather data.

Inference: The process of drawing logical explanations about what something means.

Hypothesis: A testable statement and possible explanation of an event based on prior knowledge and observations

Prediction: A prediction is a statement or claim that a particular event will occur in the future. Usually written as an If /Then statement.

The Scientific Method: a method of investigation involving observation and theory to test scientific hypotheses

Types of Observations:

What kinds of observations is he making?

Kinds of DATAQuantitative: produces numerical data that can be comparatively analyzed in graphs and tables

a. Tables: Title Table, Columns & Rows have titles

b. Graphs: -3 main types: line Graphs (measures change/ time) bar (used for comparing groups) circle (pie) (shows %)Qualitative: Descriptive data; written descriptions of observations

Observation Vs.Inference Activity

Mrs. Wade will be absent for the rest of the term. She won the lottery and thus decided to take a cruise around the world with her friends, Mrs. Walton and Mrs. Fernandez. She has left each team a bag personal items. She would like you to make 2 observations and two inferences about the contents (you have 5 minutes for this activity).

Non-related example: You observed that the ground was wet. Therefore, you infer that it had just rained.

Applying The Scientific Method

make observations /state problem

analyze results

form hypothesis

design controlled experiment

collect data

may supporthypothesis

draw conclusion /publish

may not supporthypothesis

form a newhypothesis

The Scientific Method

Students (state the problem)

Hate (hypothesis)Every (experiment)Dumb (data)Class (conclusion)

B. Parts of a Controlled ExperimentTypes of Variables Independent variable (on x-axis)

(aka Manipulated variable): a factor that is manipulated/determined by experimenter to see what the result will be

Dependent variable (on y-axis)(aka Responding variable): a factor that responds to the changes in the independent variable what the experimenter is looking for

Name those variables!

Independent Variables

Descriptions

Dependent Variables

Descriptions

Cause \EffectBefore AfterInput Output

What you doIF

What happensTHEN

In other words…

Dependent Vs. Independent Variables

Control Group: the group for which the testing conditions are not applied (may receive the Placebo).

Experimental groups: the groups where all conditions are held constant EXCEPT the one being tested

Controlled variables: (controls) Variables that the experimenters keep the same throughout the experiment.

Parts of a Controlled Experiment

An Example ExperimentMrs. Fernandez’s son, Dominick, would like to

know what will happen to his gummy bears if he places them in water. So, he obtains three (3) gummy bears (all are of the same brand). He places one in 20 mls of water for 3hrs, the other for 12 hrs, and the last for 24 hrs. He uses a 25ml graduated cylinder each bear.

0 mL 3 mL 6 mL

Your Turn….What is the independent variable in

Dominick’s experiment? In what axis do graph it?

What is the dependent variable in the experiment? In what axis do you graph it?

What are the controlled variables in the experiment?

C. Drawing a ConclusionThe conclusion should always have two main parts.

Confirm or reject the hypothesisWas the hypothesis correct?

Overall statement of what was learnedWhat happened and why did it happen?

What’s the main idea?

D. Publishing Results

When a hypothesis has been tested and supported many times, a theory may be developed and published.

A Theory is the best explanation science has to offer about a problem after much experimentation and collection of facts.

A scientific Law explains a natural phenomena and is consistently observed

III. Other things to keep in mind:

A. Always use metric system!Distance: metersVolume: litersTemperature: oCMass: grams

KILO1000Units

HECTO100

Units

DEKA10

UnitsDECI

0.1Unit

CENTI0.01Unit

MILLI0.001Unit

MetersLitersGrams

Ladder Method

How do you use the “ladder” method?

1st – Determine your starting point.

2nd – Count the “jumps” to your ending point.

3rd – Move the decimal the same number of jumps in the same direction.

4 km = _________ m

12

3

How many jumps does it take?

Starting Point Ending Point

4.1

__.2

__.3

__. = 4000 m

Gummy Bear LabRead lab directions in lab hand-out and on

boardConduct the lab.Clean up (everything must be spotless when

lab is completed).Graph and answer questionsTurn in assignment.

Redi’s Experiment onSpontaneous Generation

OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.

HYPOTHESIS: Flies produce maggots.

PROCEDURE

Controlled Variables:jars, type of meat,location, temperature,time

Manipulated Variables:gauze covering thatkeeps flies away from meat

Uncovered jars Covered jars

Several days pass

Maggots appear No maggots appear

Responding Variable: whether maggots appear

CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

Identifying VariablesTwo groups of students were tested to

compare their speed working math problems. Each student was given the same problems. One group used calculators and the other group computed without calculators.

What is the independent/manipulated variable?

What is the dependent/responding variable?

What is the controlled variable?

Identifying VariablesA study was done with an

electromagnet system made from a battery and wire wrapped around a nail. Different sizes of nails were used and the number of paper clips that the electromagnet could pick up was measured.

What is the manipulated variable?What is the responding variable?What are the controlled variables?

Identifying VariablesA study was attempted to find if the length of the string in a string telephone affected its sound clarity.

What is the independent variable?What is the dependent variable?What are the controlled variables?

Your Turn..Do the next three examples on your

own and see how well you understand the concept.

Identifying VariablesAn experiment was performed to

determine how the amount of coffee grounds could affect the taste of coffee. The same kind of coffee, the same percolator, the same amount and type of water, the same perking time, and the same electrical source were used.

What is the manipulated variable?What is the responding variable?What are the controlled variables?

Identifying VariablesStudents of different ages were given

the same puzzle to assemble. The puzzle assembly time was measured.

What is the independent/manipulated variable?

What is the dependent/responding variable?

What is the controlled variable?

Identifying VariablesA study was done to find if different tire treads affect the braking distance of a car.

What is the independent variable?What is the dependent variable?What is the controlled variable?

What is the Diff?

A scientific Law explains a natural phenomena and is consistently observed

The law of gravity & Newton's Law’s of Motion

A Theory is a well tested and complex explanation based on much experimentation and collection of facts-

The theory of evolution & theory of relativity

But That’s NOT All ALL!How is THEORY used in everyday speech that is scientifically incorrect?

Michael might say that he has a theory that Mrs. Wade will yell at the class today…

What would be a more ACCURATE word to use?

If he had made the same statement but had replaced theory with hypothesis, THEN he would be scientifically correct!

Oh no… Here come the metric problems!

Practice, practice, practice until your good becomes your better and

your better becomes your best!

Metric Units

The basic unit of length in the metric system in the meter and is represented by a lowercase m.

Standard: The distance traveled by light in absolute vacuum in 1⁄299,792,458 of a second.

Metric Units

1 Kilometer (km) = 1000 meters

1 Meter = 100 Centimeters (cm)

1 Meter = 1000 Millimeters (mm)

Which is larger?

A. 1 meter or 105 centimeters

B. 4 kilometers or 4400 meters

C. 12 centimeters or 102 millimeters

D. 1200 millimeters or 1 meter

Click the image to watch a short video

about the meter.

Measuring Length

Ruler: http://www.k12math.com/math-concepts/measurement/ruler-cm.jpg

How many millimeters are in 1 centimeter?

What is the length of the line in centimeters? _______cm

What is the length of the line in millimeters? _______mm

What is the length of the line to the nearest centimeter? ________cm

HINT: Round to the nearest centimeter – no decimals.

1 centimeter = 10 millimeters

Metric Units

Mass refers to the amount of matter in an object.

The base unit of mass in the metric system in the kilogram and is represented by kg.

Standard: 1 kilogram is equal to the mass of the International Prototype Kilogram (IPK), a platinum-iridium cylinder kept by the BIPM at Sèvres, France.

Metric Units

1 Kilogram (km) = 1000 Grams (g)

1 Gram (g) = 1000 Milligrams (mg)

Which is larger?

A. 1 kilogram or 1500 grams

B. 1200 milligrams or 1 gram

C. 12 milligrams or 12 kilograms

D. 4 kilograms or 4500 grams

Click the image to watch a short video

about mass.

Kilogram Prototype

Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using electronic balances to find the mass of various objects in this course.

A weigh boat, paper towel of some container with be placed on the balance first and you will tare it, zero it out. The the objects are placed in the container and on the scale. The digital read-out has two decimal places, which is the mass of the object in grams.

Measuring Mass – Electronic Balancea- make sure the balance reads 0.00 g

b-place weigh boat or container you will use to hold the material that is to be massed on balance and press ON button just long enough for the read-out to once again show 0.00 g (tare weigh boat)

c. remove the weigh boat and put the material in it

d. carefully place full weigh boat on balance and read to 2 decimal places

e- remove items, clean up, & zero out balance

Metric Units

Volume is the amount of space an object takes up.

The base unit of volume in the metric system in the liter and is represented by L or l.

Standard: 1 liter is equal to one cubic decimeter Metric Units

1 liter (L) = 1000 milliliters (mL)

1 milliliter (mL) = 1 cm3 (or cc) = 1 gram*

Which is larger?

A. 1 liter or 1500 milliliters

B. 200 milliliters or 1.2 liters

C. 12 cm3 or 1.2 milliliters*

Click the image to watch a short video

about volume.

* When referring to waterLiter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif

Measuring Volume

Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gifBottom Image: http://morrisonlabs.com/meniscus.htm

We will be using graduated cylinders to find the volume of liquids and other objects.

Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water.

What is the volume of water in the cylinder? _____mL

What causes the meniscus?

A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides.

Measuring Liquid Volume

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Pay attention to the scales for each cylinder.

Measuring Solid Volume

10 cm

9 cm

8 cm

We can measure the volume of regular object using the formula length x width x height.

_____ X _____ X _____ = _____

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We can measure the volume of irregular object using water displacement.

Amount of H2O with object = ______

About of H2O without object = ______

Difference = Volume = ______

KILO1000Units

HECTO100

Units

DEKA10

UnitsDECI

0.1Unit

CENTI0.01Unit

MILLI0.001Unit

MetersLitersGrams

Remember the Ladder Method

How do you use the “ladder” method?

1st – Determine your starting point.

2nd – Count the “jumps” to your ending point.

3rd – Move the decimal the same number of jumps in the same direction.

4 km = _________ m

12

3

How many jumps does it take?

Starting Point Ending Point

4.1

__.2

__.3

__. = 4000 m

Write the correct abbreviation for each metric unit.

1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____

2) Meter _____ 5) Millimeter _____ 8) Centimeter _____

3) Gram _____ 6) Liter _____ 9) Milligram _____

Try these conversions, using the ladder method.

10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm

11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km

12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg

13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm

14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

Lets Practice Metric Conversions!!!

MicroscopesAround 1590, two Dutch eye glass makers, Zaccharias Janssen and his father Hans put several lenses in a tube and invented the compound microscope (which is a microscope that uses two or more lenses). 

Differentiate between Compound Light Microscopes and Electron Microscopes

Compound Light Electron

How is object viewed?

________ passes through object

beam of _______ illuminates object

What is the magnification?

_______ x ______up to ______x

light electrons

eyepiece objective

2000much greater magnification

More on MicroscopesThe eyepiece or ocular lens usually has a magnification of 10 times (10x)

Total magnification is determined by multiplying the eyepiece magnification times the objective lens

Label the parts of the microscope:

a- eyepieceb- stagec- diaphragmd- coarse adjustmente- fine adjustmentf- armg- objectiveh- base

a

bc

d

e

fg

h

The two lenses in compound microscopes are eyepiece (ocular) and objective (although there may be more than one)

You always carry a microscope with two hands- grasping the arm and the base

The specimen is placed on a slide and onto the stage when viewed

More on Microscopes

In the microscope’s the field of view is always a circle

ALWAYS label total magnification on your drawings

Then label nameof specimen andidentified structures

More on Microscopes

Measuring the microscope field of view on lowest power-

1.Place a clear plastic ruler with mm markings on top

of the stage of your microscope.  2.Using lowest power objective, focus your image.  3.Count how many divisions of the ruler fit across the diameter of the field of view.  4.Multiply the number of divisions by 1000 to obtain the field of view in micrometers (µm). Record this in µm (micrometers) (1mm = 1000 µm)

More on Microscopes

Microscopes

What is a light/compound microscope?

Click on the link below for more microscope facts

compound microscope facts

MicroscopesWhat is an electron microscope?

What is the difference between TEM (transmission electron microscope) and a SEM (scanning electron microscope)?

Allows scientists to view a universe too small to be seen with a light microscope. They don’t use light waves; they use electrons (negatively charged electrical particles) to magnify objects up to two million times.

TEMs allows beams of electrons to go through the specimen while SEMs beams of electrons bounce off of the specimen and result in a 3D image. All images are black and white…why?

Electron Microscope game

microscope game

Click the link!