What is Science?

What is science?

What is Biology?

Are they the same?

Do they share the same goals?

Science is…• Science is a term that goes beyond simple

definitions

• It tries to

– solve the worlds problems

– answer the worlds questions,

– and yet its limits outstretch the universe…

• It is everywhere… involves everything

Go for the goal…

• We could just say science is everything… but that oversimplifies our complex field.

• So instead, we define it by its goal

• Your book defines the goal of science as:• The investigation and

understanding of the natural world in order to explain events and questions.

• In our class the goal of science is:

So… What is Science?• Science is an organized way of using Evidence

to learn about the world around us.

– This is what is meant by NATURAL reasoning and a NATURAL world and universe

– This is why we do not teach religion in a science classroom

• Religion is based in FAITH. Science is based in evidence found within nature

• Do not confuse faith with fiction… Just because religion is faith-based does not make it fake, it just makes it non-scientific…

An Organized Way

• Science has a specific method for carrying out its processes called the scientific method

• If done properly, the scientific method can be used in nearly every aspect of life.

– It is not just a method, it is a way of thinking… It is a way of living

• It all starts with a hypothesis…

The Scientific Method of Thinking

Hypothesis?

A Scientific Hypothesis is…

• It must be TESTABLE!

• It should not be phrased as a question

• Sometimes it requires multiple experiments to test completely

• A hypothesis that is incorrect can tell a lot!!!

Theory

• If your hypothesis proves correct, it is called a theory.

– NOT A FACT!

– There are NO facts in science

– Only theories that have not yet been incorrectly proven

Longest Running

• The oldest and longest believed scientific FACTis that the universe is geocentric (geo= earth, centric= centered)

• Science is ALWAYS changing and is not based on FACTS!

• And Scientists must forever be bettering there experiments, methods, and ideas

As society evolves and science grows we know one thing to be a true fact… Facts tend to close the mind and hinder the goals of science!

A theory gone wrong…

• For hundreds of years, society believed that many lesser forms of life came from circumstantial nonlife

• Maggots came from meat setting on a table and mold would form if you left bread uncovered.

• It even went as far as to say mice form from food being left out in a barn…

Why question the norm?

• This theory was called spontaneous generation because it said lesser life (like mold, insects, and rodents) formed from nonlife…

• As ridiculous as this theory may seem to our modern society, it was accepted as fact for centuries

Simple Observations

• Francesco Redi conducted simple observations by noting that meat seemed to have maggots only after flies landed on the meat

• Other scientists that we will talk about later in the semester like Rudolf Virchow, Anton van Leuwenhoek, and Lorenzo Spallanzani also began to attack this societal theory

Louis Pasteur • The theory of spontaneous was eventually put

to rest by the experiments done by Louis Pasteur.

• Pasteur created a special flask which ended the debate

• The flask contained gravy, unsealed in flask, with a swan neck

• This specialized flask allowed air flow but prevented bacteria covered dust from entering the gravy

• This allowed the gravy to stay free of microbes

Open Mind and Good Experiments• The experiments done by Redi, Virchow, van

Leuwenhoek, Spallanzani, and Pasteur were not overly complicated,

• They just didn’t accept what society considered a fact

• They observed a problem• Controlled the experiment• Manipulated one SINGLE VARIABLE• Collected the data• Formed a conclusion• And in some instances, formed a new hypothesis

and experiment

Good Science Method

• Starts with the observation of a problem

• A testable educated guess (Hypothesis) is formed as to what the answer may be

• An experiment is formed with all variables controlled (kept the same) except one (the manipulated/independent variable)

• Data is collected (the dependent variable)

• A conclusion is drawn

• Occasionally a new hypothesis/experiment must be created…

What is Biology?

• Biology is a branch of science like astronomy, psychology, chemistry, and physics…

• It has the same overall goals as science (using natural reasoning to answer questions)

• However, biology focuses on studying, answering, and using natural evidence to better understand Life

What does it mean to be alive?

Characteristics of Life as We Know It

• Are made up of one or more units called cells

• Reproduce

• Based on a Universal Genetic Code

• Grow and develop

• Obtain and use energy

• Respond to their environment

• Maintain a stable internal environment

Living Things Are Made Up of Cells

• Small self-contained units called cells

• All are living material enclosed by some form of a membrane that separates it from its surroundings

• Filled with living matter

• Smallest unit of life

Reproduce

• All living things can reproduce– Make new organism of the same species

• Sexual Reproduction– Requires that 2 cells from different individuals

unite to produce the first cell of a new individual

• Asexual Reproduction– A single organism may reproduce without the aid

of another• This can be as simple as just one individual dividing to

make 2 individuals

Based on a Universal Genetic Code

• All of life uses a long double strand of nucleic acids to create their blueprints of life

• We call this group of nucleic acids Deoxyribonucleic Acid (DNA)

– it is assisted by a nucleic acid that is generally found as a single strand called Ribonucleic Acid (RNA)

DNA & RNA

Living Things Grow and Develop

• All living things, at one stage or another, are capable of growth and development

• Often times, even after something stops growing, it still continues to add new material

• With growth comes aging

– Aging is an organism becoming less efficient at the processes of life

Obtain and Use Energy

• Living things obtain energy from their environment, or their environment, and use that energy to grow, develop, and reproduce.

• They use energy to build the substances that make up their cells

• Anabolism: The process of living things putting things together or synthesizing complex substances

• Catabolism: The final break down of complex substances, into simpler ones, in order to release energy

Remember

• Money = Energy in Biology

• The cheaper a process is, the better it is for your check book

Mouse vs. Elephant

• Which of the above organisms would you expect to have a harder time staying warm when it gets cold outside

Surface Area

• The smaller an organism is the larger its surface area.

– The higher the amount of surface exposed to the outside elements (vs. internal mass)

– It is a surface to volume ratio

– The larger the organism the greater the volume

• Small organisms have a high surface area

• Large organisms have a small surface area

Living Things Respond to Their Environment

• Response to an environment has become essential for life

• Selective pressures eliminate and create species all the time

• The process by which organisms respond to stimuli in ways that keep conditions in their body suitable for life is called Homeostasis

• It is through homeostasis that our bodies are able to remain suitable for life

• Example: Tropisms (Gravi, photo)

Maintain Internal Balance

• When we go outside on a cold day, our body temperatures do not drop drastically (which is a good thing)– Why?????

• Nearly all life has process inside their bodies that keep variables like temperature and water levels constant, despite outside conditions…– This is called

BIOLOGY

• Bio = Life

• logy = Study of

• Bio-logy = The Study of Life

Biologist

• So what is a “Biologist??”

• A biologist is somone who uses the SCIENTIFIC METHOD and CRITICAL THINKING to study

Forming an inference…

Technology Advancements

• Science is restricted by a lack of technology

• As our scientific tools (technology) advance, so advances our ability to do science… to invent… to understand… to fix…

• Think about how much science changed with the advancements in a simple microscope…

Compound Microscopes

• Compound Light Microscope: Uses 2 Lenses to make up one larger image

– Will have a LIMIT of RESOLUTION• The point at which further magnification will cause a decrease in

resolution (BLURRY!)

– Even a perfect compound microscope will have a Limit of Resolution (LoR)

• One of the best ways to view an item in a Compound Microscope is by staining them

• The average compound microscope’s Limit of Resolution is = .2 micrometers (an average cell = 10 micrometers)

Electron Microscopes

• SEM: Scanning Electron Microscope– A beam of electron particles scan back and forth

across an image and are picked up by receptors• Gives a 3-D image of the outside of an item

• Exceptional for viewing tiny organisms

– Drawbacks:• Organism must be dead and completely dry

• Only works if organism is placed in a vacuum

• Not cheap

SEM

SEM

SEM

Electron Microscopes

• Transmission Electron Microscopes:– Shines a beam of electrons that magnifies the

image onto a fluorescent screen

– Excellent for internal magnifications and cell parts

• Drawbacks:– Object must be dead

– Object must be completely free of moisture

– Object must be sliced extremely thin

– Object must be placed in a vacuum

TEM

TEM

TEM

Scanning Probe Microscope

• Very new microscope discovered in the 80s

• Do not use lenses

• Use an insanely fine tip to scan the surface of an object

• Can magnify so well that it actually allows the view of individual atoms

• Does not require the object to be placed in a vacuum

SPM or PM

SPM

SPM

SPM

SPM

Metric System

• Science use SI units when collecting data and doing calculations– SI = International System of measurements

• This means that it is used by all nations…

• Why is it not called IS units?????

• It is based on a Base 10 System– This means it is arranged in multiples of ten

• There are exactly ten units between centimeters and millimeters

• EVERYTHING we do in here should be in SI units!

Mars Probe