Biological Questions What is science Science is The continual effort to discover and increase human understanding of how reality works The systematic process allows us to better understand past events and predict future events of a similar kind ID: 783111
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Slide1
Biology in the 21st Century
Slide2Biological Questions
Slide3What is science?
Science is…
The continual effort to discover and increase human understanding of how reality works
.
The systematic process allows us to better understand past events and predict future events of a similar kind.
Science is not static, it is ever changing.
Slide4What do you think?
Define the following…
Fact
Hypothesis
Law
Theory
Slide5Fact
A scientific fact is a controlled, repeatable and/or rigorously verified observation
, probability of “truth” is incredibly high—little room for doubt.
An example of current facts:
All things with mass have gravity.
Gravity is an attractive force.
Slide6Fact
Sometimes new discoveries make us have to re-evaluate and/or revise our “facts” – THAT’S SCIENCE!
Former
Fact
The
Earth is flat.
Slide7Hypothesis
A suggested explanation;
a proposal based on reason that predicts a possible correlation between multiple phenomena (incidents, events, observations, etc.)
Slide8Law
Notes only that something happens, happens consistently and across the universe
; usually simply stated; frequently can be stated
mathematically
.
Example:
Newtons 2
nd
Law: F = ma
A body of mass (
m)
subject to a force (F) undergoes an acceleration (a) that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass.
Slide9Theory
Notes why something happens, explains why laws and facts are true, a framework about a class or group of phenomena
, sometimes valuable to predict.
Theories are never “proven”—they are
confirmed
by overwhelming data, all theories, like all ideas in science, are subject to correction.
Slide10Theory
Examples:
Plate Tectonic Theory
Atomic Theory of Matter
Germ
Theory
of DiseaseTheory of Natural Selection
HOW ARE THEY DIFFERENT THAN CONSPERACY THEORIES?
Slide11Diversity of Life
Life is found almost everywhere on earth
.
There are organisms that live in hydrothermal vents in the deepest part of the ocean, in thousands-of-years-old Antarctic ice.
Slide12The Biosphere
All living things and all the places they are found on Earth make up the biosphere
.
Every part of the biosphere is connected to another.
Slide13Biodiversity
The variety of life in the biosphere is biodiversity
.
Greater biodiversity is usually found near the equator.
Why do you think this is?
Over 2 million species have been identified, but scientists estimate that tens of millions of species are left to be identified.
Every year, biologists discover about 10,000 new species.
Slide14Characteristics of Living Things
Biology is the scientific study of all forms of life, or all types of organisms.
An organism is any individual living thing
.
Which of these is a living thing? Why is it living and the other non-living?
Slide15Characteristics of Living Things
All living organisms share these characteristics
:
They are made of
cells
.
They
need energy
.
They
respond to their environment
.
They
reproduce and grow
.
They
maintain a stable internal environment
.
They
change over time
.
Slide16Unifying Themes
Biology has several
unifying themes:
All levels of life have systems of related parts.
Structure and function are related in biology.
Organisms must maintain homeostasis to survive in diverse environments.
Adaptation over time explains the unity and diversity of life
.
Slide17Biology is a Process of Inquiry
Scientific thinking begins with
observation
.
Observation uses the senses—hearing, sight, smell, etc.
It involves repeatedly recording the information over time
.
Slide18Thinking Like a Scientist
Over time,
data
is gathered.
Qualitative data = descriptions and involves characteristics that can’t usually be counted.
Quantitative data = expressed as numbers, obtained by counting or measuring.
Slide19Thinking Like a Scientist
From a large amount of data—an
Inference
is made.
An Inference is a logical interpretation of phenomena
It is based on prior knowledge or experience.
Slide20Explaining and Interpreting Evidence
After initial observations—a scientist will from one or more
Hypotheses
.
A hypothesis is:
Based on prior knowledge
Based on inference
Informed
Creative and Imaginative
TESTABLE!
Controlled experiments
Collecting more data
Slide21Spontaneous Generation
Up until the late 1800’s some people believed that life generated from non-life.
Slide22Redi’s Experiment
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 that
keeps 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.
Slide23Spallanzani’s Experiment
Spallanzani tested Redi’s results with an experiment of his own.
Gravy is boiled.
Flask is
open.
Gravy is teeming
with microorganisms.
Gravy is boiled.
Flask is
sealed.
Gravy is free of
microorganisms.
Slide24Pasteur’s Experiment
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is teeming with microorganisms
Slide25Modern Tools of Biology
Microscopes
Medical Imaging
Modeling on computers
Molecular Genetics
The study and manipulation of DNA.
Genomics = the study and comparison of genomes within and across species.
Slide26Biology and Your Future
Food
70-75 % of processed food contains some genetically engineered ingredients.
45% of U.S. corn is genetically engineered.
60% of adults in the U.S. are overweight or obese.
Slide27Biology and Your Future
Environment and health
Recent studies have indicated that chemicals present in re-used water can cause hormonal deformities in certain plant and animal species.
It has been suggested that hormones present in certain meat products can cause children to hit puberty quicker.
Slide28Biology and Your Future
Biotechnology
Includes the use of microorganisms to make bread and cheese.
Used in medicine, agriculture, forensic science, and many other fields.
The use of DNA testing in criminal courts is an example of biotechnology.
Slide29Biology and Your Future
Transgenic Organisms
Organisms that have genes from more than one species, or have altered copies of their own genes are transgenic organisms.
Transgenic bacteria is used to create insulin that treats diabetes.
Transgenic cows and sheep create antibodies and proteins that humans can use.
Transgenic plants are resistant to insects and can reduce or end the need of pesticides.
Slide30Biology and Your Future
Genetic Screening
These tests can indicate whether individuals or their potential offspring may be at risk for certain diseases or genetic disorders.
This can help with early diagnosis and treatment.
Who should have access to the information? What genetic quirks should be considered disorders? Could genetic information be used to design children?
Slide31Science as a Way of Knowing
Science is not a collection of immutable truths.
Science is an ongoing process.
Scientists need to be skeptical, open minded, and analytical.
Science and human values often intersect. The knowledge we collect today affects the lives of people tomorrow.