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Welcome to Biol406
Paloma Valverde, PhD
[email protected]
Office: Ira Allen Building, Room 218
Course Description
Biol 406 introduces fundamentals principles
of biology
Cell structure
Metabolism
Reproduction and Genetics
Classification of living organisms
Animal anatomy,physiology and
evolution
The influence of biology in our society.
Instructional Methodologies
This course can be defined as a hybrid since approximately
30-40% of it involves online-like activities and/or online
delivery.
This course will use blackboard and connectplus to post
grades, announcements, assignments, power point
presentations, lab handouts and interactives.
Students will be required to keep a lab manual including
wet and dry lab-related activities.
Students will work individually or in groups to discuss or
write about current topics in biology. Students will also
deliver a final project to the class by using lecturecapture technology. Office hours will be available both
online and on-site.
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Online component of the course
Labs 1, 2, 7, 10 and 13 are online labs.
Special topics sessions on Fridays are
online
You do not have to go to class/lab on those days, but you
have to complete the activities the day of the lab or
special topic.
At the completion of the activity: Send email to me
indicating you completed it and did not have any
problems
If Problems with the activity: Ask me and I will help you
(during those sessions you can come to my office or call
me). Use google chat/office phone
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Required Text Book and Online
Technologies
http://connect.mcgrawhill.com/class/p_valverde_spring2011
Text book is called: Biology, 10th Edition,
Mader, McGraw-Hill
Link above: electronic book and online
assignment technology (buy
Connectplus) $97
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Other needs
• Get a free gmail account to be able to use
google voice/video chat and google docs.
Go to: mail.google.com
To create an account if you do not have one
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Blackboard account
• Lab handouts
• Power point presentations
• Assignments
• To register for the first time:
Username: your wentworth username
Password: 654321
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Paloma Valverde, PhD
Assistant Professor, Sciences
Office Location: Ira Allen Building 218
Email: [email protected]
Office hours:
M/T/Th/F
12-12:50 pm
Office phone: 617-989-4439 (and to contact by Google voice/video chat,
Gmail: [email protected])
Biology, Life and The Scientific
Method
Week 1 lecture: Chapters 1
Outline
• What is biology?
• What are the properties of life/living
organisms?
• How biologists use the scientific method
to study life
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What is biology?
• In its broadest sense, biology is the study
of life and consists of many disciplines
(biochemistry, cell biology, zoology,
botany, ecology…)
Properties of Living Organisms
Living things shared 7 characteristics:
– are highly organized
– are composed of 1 or many cells (a cell is the
basic unit of life)
– interact with other living organisms and the
environment, and respond to them
– can grow and reproduce
– acquire materials and use energy to perform work
– maintain a state of internal balance within the
tolerance range of the organisms.
– adapt and modify with time (evolution) to make
organisms suited to their way of life
Biosphere
Levels of
Organization
Ecosystem
Community
Population
Organism
Organ system
Organ
Tissue
Cell
Molecule
Atom
Smallest
unit of matter
Smallest
unit of life
A Cellular level
Muscle cell
B Tissue level
Muscle tissue
C Organ level
Heart
D Organ system level
Circulatory system
E Organism level
Many organ systems
functioning together
1)A population consists of all organisms of the same species (look alike and
can interbreed) in a particular area
2) A community consists of all of the local interacting populations
3) An ecosystem consist of aspects of a community and the physical
environment (soil, atmosphere, etc)
4) The biosphere (our planet Earth) consists of different ecosystems that
interact with each other. The Biosphere is the zone of air, land and water
where organisms exist
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Energy is needed to survive
• Energy – required to maintaining organization and
conducting life-sustaining processes
– The sun is the ultimate source of energy for nearly all life on Earth
– Certain organisms, such as plants, capture solar energy to carry
on photosynthesis (autotrophs). Photosynthesis transforms solar
energy into chemical energy by producing Organic Molecules
(with C)
– Chemical energy is used by other organisms by the process of
cellular respiration e.g. animals (heterotrophs)
– Metabolism is all the chemical reactions that occur in a cell or
in an organism to maintain life.
– Two categories: Catabolism (breaks down organic molecules), ex
in cellular respiration; anabolism uses energy to contruct large
molecules such as proteins and nucleic acids.
Homeostasis is another
characteristic of life
– Homeostasis - Maintenance of internal
conditions within the tolerance range of the
organism (temperature, moisture level, pH…)
Living Things: Respond to Stimuli
• Living organisms interact with other living organisms and
with the environment and respond to stimuli or changes
• Response ensures survival of the organism and it often
results in movement
– Vulture can detect and find carcass a mile away and soar
toward dinner
– Monarch butterfly senses approach of fall and migrates south
– Microoganisms can sense light or chemicals
– Leaves of plants follow sun
• The collective responses of an organism constitute the
behavior of the organism
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Living Things: Reproduce and Develop
• Organisms are born, grow and then die
• All living organisms must reproduce to ensure
continued existence and maintain population
• Developmental instructions encoded in genes
• Composed of DNA
Living Things: Adapt to Change
• Adaptation
– Any modification that makes an organism more suited
to its way of life
– Organisms become modified over long period time
• Respond to environmental changes by developing
new adaptations
Living things: Evolve
• Because organisms can adapt, they can also evolve.
• Evolution: modification of a species over generations
• Despite diversity, organisms share the same basic
characteristics
– Composed of cells organized in a similar manner
– Their genes are composed of DNA
– Carry out the same metabolic reactions to acquire
energy
• This suggests that they are descended from a common
ancestor organism that lived on the Earth millions of years
ago
How does Biology study Life?
1) Many biological studies use the scientific
method and lab experimentation
2) Statistical methods are essential scientific
tools
3) Not all forms of inquiry in biology involve
lab experimentation, some are discoverybased or may be involve tests by
observation.
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Biology and the Scientific Method
Biology is the scientific study of life. Many biological studies
involve the use of the scientific method.
Steps in the scientific method:
• Based on careful observations, scientists can develop a
hypothesis
• A hypothesis is a possible explanation to an observation
that allows for predictions to be made.
• Scientists do experiments and data collection to test the
validity of the hypothesis (by seeing if the predictions come
true). If the predictions do not come true the hypothesis is
falsified (proven wrong)
• Scientists reach to a conclusion
Developing a good Hypothesis
• A hypothesis must be testable (able to be proven
valid through experiments) and falsifiable (able to
be proven not valid)
• Sometimes a biologist will develop a main
hypothesis and alternative hypothesis and do two
or more experiments to save time and resources
• Scientist can develop experiments to prove that a
main hypothesis is right and experiments to falsify
another hypothesis.
• For example,
– Observation: Your flashlight
doesn’t work
– Question: Why doesn’t your
flashlight work?
– Hypothesis 1: The batteries are
dead
– Hypothesis 2: The bulb is burnt
out
• Both of these hypotheses are
testable with experiments
• Experiments allow to falsify the
hypothesis (invalid hypothesis)
or not falsify the hypothesis
(valid hypothesis)
Observations
Question
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Prediction:
Replacing batteries
will fix problem
Prediction:
Replacing bulb
will fix problem
Experiments
Test prediction
Test prediction
Test falsifies hypothesis Test does not falsify hypothesis
Controls, Variables and Controlled
experiments
The experiment (s)
-tests the hypothesis
-must be carefully designed to test only one
variable (factor that influences the experiment,
for example temperature) at a time
-In a controlled experiment you will compare IN
PARALLEL an experimental group (in which one
variable is changed) with a control group (in
which the variable is not changed)
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Example of Controlled Experiment
Example: You have to test a new miracle food in a
group of overweight poodles.
Variable: Miracle food
Control group: Half of the poodles will be fed with regular food
Experimental group: The other half of the poodles will be fed
with miracle food
Results of the experiment:
Control group: Overweight Poodles gain weight
Experimental group: Overweight Poodles lose weight
Conclusion: The miracle food helps overweight poodles lose
weight
Theories in Science
A Scientific Theory is the best current
explanation for an observation that is
supported by a broad range of observations,
experiments and data (a much greater body
of evidence than a hypothesis)
A hypothesis may become a theory if a lot of
evidence is found for its validity: An example
of this is “Darwin’s theory of natural
selection”
Example of Scientific Inquiry in Biology: Darwin and
his theory of evolution
Darwin was an English naturalist
that served on a 5 years-long
mapping expedition around
coastal South America in 1831
(he was 22 years old) on
board of the Beagle.
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Darwin’s Evidence: The beaks of the Galapagos
Finches
Darwin observed 14 species of finches in the Galapagos
Islands, and noticed variations in their beaks and in what
they ate in the different islands.
Darwin proposed that the different beaks represented
evolutionary adaptations that improved their ability to eat
the foods available in the different islands
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Darwin formulated the hypothesis that evolution
occurs because of natural selection
evolution: modification of a species over generations
natural selection:
1)Individuals that are best adapted to their
environment are more likely to survive and
reproduce
2) Over time, more individuals in a population will
have the advantageous traits
In other words, the natural environment “selects” for
beneficial traits: “The survival of the fittest”
Post-Darwin Evolution Evidence
- New fossils are found all the time that
suggest evolution has happened
- Anatomical similarities between different
organisms also suggest we have had a
common ancestor
Darwin’s initial hypothesis became a theory
because of the large amount of evidence
that supported it.
The Scientific Method in Biology
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Observation
New observations
are made, and previous
data are studied.
“possible and
testable
explanation for
an observation”
Hypothesis
Input from various
sources is used to formulate
a testable statement.
Experiment/Observations
Conclusion
The hypothesis is
tested by experiment
or further observations.
The results are analyzed,
and the hypothesis is
supported or rejected.
Scientific Theory
Many experiments and
observations support a
theory.
“best current explanation
for an observation”
“lots of evidence
supports its validity”
Lab 1 & Special Topic 1
(R) Lab 1: Tutorial about the Scientific method
We will do this one face-to-face in the lab (ANXNO003), but
in the future you can do online labs on your own)
Need a computer/Work in group.
Do online with your computer (use lab handout on
blackboard) but write answers in hard copy
Lab handouts collected and graded twice during the
semester (electronic handouts are not accepted)
(F) Special topic 1 and Assignment 1:
Exobiology/Astrobiology; the scientific method
in action We will do those one face-to-face in class but in
the future you can work on your own or in groups on the
special topics and send by email to me ([email protected])