What is Biology?

Biology: The Study of Life

• Biology is the study of life.– (prefix ????)

The Science of BiologyThe Science of Biology

What Do Biologists Study?

1. The interactions of living things

Ex. What does it need to survive?

2. The interactions of living things & the environment

Ex. How does one affect the other?

3. Problems and possible solutions

Ex. What can we do about endangered species?

Major Branches of Biology• Ecology: the study of the environment • Botany: the study of plants• Zoology: the study of animals• Anatomy & Physiology: the study of the

structures and functions of the body • Microbiology: the study of microorganisms –

Micro bi ology

• An organism is anything that possesses all of the characteristics of life.

Characteristics of Living Things:

What does it mean to be alive??

Characteristics of Living Things:

What does it mean to be alive??

• A Species: a group of organisms that can interbreed and produce fertile offspring

All living things:• have an orderly structure

• produce offspring

• grow and develop

• Maintain homeostasis (stat or statsis)

Characteristics of Living ThingsCharacteristics of Living Things

• React to stimuli

• Use energy

• All living things have biological organization.

• Whether an organism is made up of one cell or billions of cells, all of its parts function together in an orderly, living system.

Living things are organizedLiving things are organized

• One of the most obvious of all the characteristics of life is reproduction.

• Reproduction is the production of offspring.

Living things make more living thingsLiving things make more living things

• Reproduction is not essential for the survival of an individual organism, but it is essential for the continuation of the organism’s species.

Living things make more living thingsLiving things make more living things

• Growth is an increase in the amount of living material and the formation of new structures.

• All organisms grow, with different parts of the organism growing at different rates.

Living things change during their livesLiving things change during their lives

• Development is all of the changes that take place during the life of an organism.

Living things change during their livesLiving things change during their lives

• Organisms live in a constant interface with their surroundings, or environment.

• The environment is the air, water, weather, temperature, any other organisms in the area, and many other factors.

• This is why Homeostasis is so important

Living things adjust to their surroundingsLiving things adjust to their surroundings

• A stimulus is anything in an organism’s external or internal environment that causes the organism to react.– ex: bee / heat

• A response is a reaction to a stimulus. – ex: swat / pull away

Living things adjust to their surroundingsLiving things adjust to their surroundings

• Living things reproduce themselves, grow and develop, respond to external stimuli, and maintain homeostasis by using energy.

• Energy is the ability to cause change.

Living things adjust to their surroundingsLiving things adjust to their surroundings

• An adaptation is any structure, behavior, or internal process that enables an organism to respond to environmental factors and live to produce offspring. • Adaptations occur through learning

• Evolution is the gradual change in a species through adaptations over time.

Living things adapt and evolveLiving things adapt and evolve

• Adaptation

• protection from the elements

• Evolution

• industrial revolution began in the middle of the eighteenth century. Since then, tons of soot have been deposited

The Methods of Biology

Biology: The Study of Life

• Scientific method common steps that biologists and other scientists use to gather information and answer questions

•organized way to answer questions about the world around us

The Scientific MethodThe Scientific Method

• 1. Observation – identification of an issue or problem that can be solved through experimentation

• 2. Hypothesis is an explanation for a question or a problem that can be formally tested.

• Not random

• An educated guess based off observations and what you already know

The Steps;The Steps;

• 3. An experiment is an investigation that tests a hypothesis by the process of collecting information under controlled conditions.

• Independent Variable – condition/item that is changed

• Dependent Variable – measurable changes (depends on the independent variable)

• Control Group – all conditions are kept the same

• Experimental Group – test group

The Steps:The Steps:

• 4.

The Steps:The Steps:

Collect and Analyze data

•Modify the procedure if needed•Confirm the results by retesting (= reliable)•Include tables, graphs, and pictures

• Scientific information can usually be classified into one of two main types, quantitative or qualitative.

Kinds of Information/Data

• Quantitative data is numerical data that may be measurements or counts.

• Quantitative data may be used to make a graph or table.

Kinds of Information/Data

Paramecium Survival Rates

Temperature

Nu

mb

er o

f p

aram

ecia

su

rviv

ing

• Observational data are often just as important in the solution of a scientific problem as numerical data.

Kinds of Information/Data

• Qualitative data are expressed in verbal form, using words to describe observations made during an investigation.

• 5. After careful review of the results, the scientist must come to a conclusion.

Thinking about what happenedThinking about what happened

• Was the hypothesis supported by the data?

• Was it not supported?

• Are more data needed?

• In science, a hypothesis that is supported by many separate observations and investigations, usually over a long period of time, becomes a theory.

Theories and lawsTheories and laws

• A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many

different investigations and observations.

• In addition to theories, scientists also recognize certain facts of

nature, called laws or principles, that are generally known to be true.

Theories and lawsTheories and laws

• Ethics : the moral principles and values held by humans.

• Society as a whole must take responsibility for the ethical use of scientific discoveries.

Science and Society: Always Remeber

• Biologists use a variety of tools to obtain information in an investigation.

Lab EquipmentLab Equipment

• Common tools include beakers, test tubes, hot plates, petri dishes, thermometers, balances, metric rulers, and graduated cylinders.

Laboratory Equipment for Measuring Liquids

BEAKER

FLASKGRADUATED CYLINDERS

(volume)

Laboratory Equipment for Measuring Solids

TRIPLE BEAM

BALANCE

(mass)

RULER

(area & volume)

DENSITY = MASS/

VOLUME

Other Laboratory Equipment

PETRI DISH

Used to culture bacteria

TEST TUBES & TONGS

PIPETTE

Used to transfer small

amounts of liquid

BUNSON BURNDER

Used to heat liquids

• More complex tools include

microscopes

– Election, light, compound light

Laboratory EquipmentLaboratory Equipment

The Compound Light Microscope

Microscope

• two lenses—the eyepiece and the objectives• The total magnification of an object - multiply

the eyepiece (10x) by the objective being used (4x, 10x or 40x)

• The diaphragm adjust the amount of light shining through the slide

• The Stage holds the slide

Focusing

• The course adjustment should be used first on only on the lowest power objective

• The fine adjustment is used to be used second and only to clarify the object on the higher power objectives

Electron MicroscopesUse a beam of

electrons to create high resolution

images

Can magnify objects 2 million times

Lab Safety• Let’s Review our Lab Safety Sheet

– Cell phones allowed out in the lab?– I can finish my lunch in the lab, as long as it is

before the bell rings?– Only closed toed shoes allowed in the lab?– Knowing where safety equipment is located in the

lab is a smart idea? – It is OK for me not to read my lab. I can just follow

the lead of my lab partner?

• A safety symbol - warns you about a danger that may exist from chemicals, electricity, heat, or procedures you will use.

Sharp Object Safety This symbol appears when a danger of cuts or punctures caused by the use of sharp objects exists.

Clothing Protection Safety This symbol appears when substances used could stain or burn clothing.

Eye Safety This symbol appears when a danger to the eyes exists. Safety goggles should be worn when this symbol appears.

Chemical Safety This symbol appears when chemicals used can cause burns or are poisonous if absorbed through the skin.

Maintaining safetyMaintaining safety

Biology: The Study of Life

Graphs

Graphs

• Graphs play an important role in analyzing and explaining data and relationships.

• easily observe trends or behavior

• X axis (horizontal)– Independent variable

• Y axis (vertical)– Dependent variable

D

• Scientists always report measurements in a form of the metric system called the International System of Measurement, commonly known as SI.

Measuring in the International System

SI Base UnitsMeasurement Unit SymbolLength meter mMass gram g

Time second sVolume liter lTemperature Celsius C

In biology, the metric units you will encounter most often are:

Measuring in the International System The metric system is based on the power of 10.

This means that each unit is ten times greater than the previous unit.

Some common metric prefixes:

• Kilo- (1000 times)

• Milli- (1/1000)

• Centi- (1/100)

Technology and Science

• Technology : the application of scientific research to society’s needs and problems.