Biology 1020:
Principles of Biology
Instructor: Dr. Scott Bowling
.
Today’s Lecture Topics
 Active
learning
 Course
syllabus / other initial
business
 Chapter
1: The Science of Biology
.
•
•
Groups of 3-4
1 sheet of paper; answer:
–
–
–
WHO ARE YOU? (first and last names)
WHY ARE YOU HERE? (in this class)
WHAT DO YOU WANT? (out of this class)
Answers are group answers, not individual – introduce
yourselves, list your names, discuss the other two
questions, then write group summaries for them.
You have five minutes – begin!
.
Chapter 1: The Science of Biology

Scientific Method

Characteristics of living things

Information transfer in living systems

Diversity of Life / classification of living
systems

Energy flow in living systems
.
Chapter 1: The Science of Biology
 Scientific
Method

Characteristics of living things

Information transfer in living systems

Diversity of Life / classification of living
systems

Energy flow in living systems
.
•
Discuss how the scientific method
works, and the difference between
inductive and deductive reasoning.
•
Come up with examples of inductive and
deductive reasoning.
•
Do NOT worry about learning the
scientific method as “step one – step
two – etc.”
.
•
Discuss testable models, including
terms for them and why “testable”
matters. How does this relate to the
supernatural?
.
Biology is Studied Using the
Scientific Method

Science is based on a systematic
thought process

uses deductive and inductive reasoning

makes testable models of how the universe
works
.
Biology is Studied Using the
Scientific Method


deductive reasoning

summarize the information at hand

draw conclusions from that information

proceeds from the general to the specific
inductive reasoning

generalization from several specific observations

proceeds from the specific to the general

must be careful, because it is impossible to prove the
accuracy of the generalization
.
Deductive reasoning

Proceeds from the general to the specific

If starting general assumptions are true,
then the conclusion must be true

Example:

All birds have wings.

Sparrows are birds.

Deduced conclusion would be:
Sparrows have wings.
.
Inductive reasoning

Drawing a generalization from several specific
observations

Proceeds from specific to general

Example:

Sparrows are birds, and they have wings.

Falcons are birds, and they have wings.

In fact, all birds that I have ever seen or heard of
have wings.

By inductive reasoning, the conclusion would be:
All birds have wings.
.
Inductive reasoning

Impossible to prove the accuracy of the
generalization

Despite this shortcoming, it forms basis of
most science
…this is the main reason why science is an
unfolding, evolving process
.
Biology is Studied Using the
Scientific Method

The scientific method in a nutshell:

summarize existing observations

make a model about how the universe
works (using those observations)

test the model

revise the model as needed and repeat
(and repeat, and repeat, and repeat….)
.
Biology is Studied Using the
Scientific Method

summarizing existing observations
may also involve collecting new
information or observations if there
aren’t enough already

then a hypothesis is made; this is a
testable model that:

explains the existing observations

makes predictions that can be tested

often more than one hypothesis is made
.
Biology is Studied Using the
Scientific Method

More observations are made to test the
correctness of the hypothesis; where possible,
an experiment is conducted

In an experiment conditions are controlled to provide a
better and more reliable test

Experimental or treatment group - the individuals
given the specific treatment or condition being tested
(may be more than one treatment group)

Control group - the individuals not given the specific
treatment (may be more than one control group)
.
Biology is Studied Using the
Scientific Method

observations and measurements are taken of
the experimental and control groups

the data are compared

the data should provide evidence to either reject
(disprove) or support (but never prove) the
hypothesis

care must be taken that the experimental and
control groups receive the same treatments
except for the specific effect being tested; avoid
things such as the placebo effect
.
Analysis of
Experiments

Experimenter must
interpret the results
(often using statistics)

Taking small sample
sizes often results in
errors in the estimate
of the entire population

The larger the sample
size, the more reliable
the results
.
The Scientific Method

Summarize existing observations (and
make new ones)

Formulate a hypothesis, a model that:


Explains existing observations

Makes testable predictions

Can never be proven true, only supported or
disproved
Test the hypothesis (experiment)
.
01.04 Scientific Method
Slide number: 2
Observation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 3
Observation
Question
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 4
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 5
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Experiment
Potential
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 6
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Experiment
Reject
hypotheses
1 and 4
Potential
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 7
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Experiment
Reject
hypotheses
1 and 4
Hypothesis 5
Hypothesis 3
Hypothesis 2
Remaining
possible
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 8
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Experiment
Hypothesis 5
Hypothesis 3
Hypothesis 2
Reject
hypotheses
1 and 4
Experiment
Remaining
possible
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 9
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Experiment
Hypothesis 5
Hypothesis 3
Hypothesis 2
Reject
hypotheses
1 and 4
Experiment
Reject
hypotheses
2 and 3
Remaining
possible
hypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 10
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Experiment
Hypothesis 5
Hypothesis 3
Hypothesis 2
Remaining
possible
hypotheses
Reject
hypotheses
1 and 4
Experiment
Hypothesis 5
Reject
hypotheses
2 and 3
Last remaining
possible hypothesis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
01.04 Scientific Method
Slide number: 11
Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
1
2
3
4
5
Potential
hypotheses
Reject
hypotheses
1 and 4
Experiment
Hypothesis 5
Hypothesis 3
Hypothesis 2
Remaining
possible
hypotheses
Reject
hypotheses
2 and 3
Experiment
Hypothesis 5
Last remaining
possible hypothesis
Predictions
Experiment 1
Experiment 2
Experiment 3
Experiment 4
Predictions
confirmed
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
.
The Scientific Method

The recursive nature of the process:

experiments provide more observations

at any time more observations may be added in
and more testable models may be produced

…this may in turn lead to more experiments, and
the process continues

this generally leads to progress towards more and
more reliable models of how nature works

creative thinking often plays a major role when
rapid progress occurs
.
Scientific Method

Hypothesis, theory, and law

A well supported hypothesis that links together
a large body of observations is considered a
theory.

A theory that links together significant bodies
of thought and yields unvarying and uniform
predictions over a long period of time
becomes considered a principle or law.
.
•
Discuss how the scientific method
works, and the difference between
inductive and deductive reasoning.
•
Come up with examples of inductive and
deductive reasoning.
•
Do NOT worry about learning the
scientific method as “step one – step
two – etc.”
.
•
Discuss testable models, including
terms for them and why “testable”
matters. How does this relate to the
supernatural?
.
Scientific Method
caveats:


Scientific models can only be proven false, never
proven true.

Correlation does not equal causation.

Testable predictions cannot include the supernatural
(the supernatural cannot, by definition, be tested
scientifically); thus, the supernatural is outside the
realm of science.

The term “theory” has a very different meaning in
science than in most everyday conversations.
.
Scientific Method

science and technology –

the goal of science is to understand nature

the goal of technology is to apply scientific
knowledge for a specific purpose
.
Chapter 1: The Science of Biology

Scientific Method
 Characteristics
of living things

Information transfer in living systems

Diversity of Life / classification of living systems

Energy flow in living systems
.
•
Explain the characteristics of living
matter to each other. Answer the “Fido”
question (will be described in class).
.
Characteristics of Living Things
Generally, life on Earth is defined such that all
living things…

are made up of cells

grow & develop

regulate their metabolism

perceive and respond to stimuli

reproduce
.
Characteristics of Living Things

All living things are made up of cells

The cell is the basic unit of life, both in structure
and function; it is living material bounded by a
membrane

Cells come from and give rise to other cells

Some organisms are unicellular; some are
multicellular
.
Characteristics of Living Things

All living things grow & develop

growth - increase in size and/or number of
cells


growth may be different in different locations
development – changes in roles of cells
during life cycle of an organism

individual changes as development proceed
throughout life
.
Characteristics of Living Things

All living things regulate their metabolism

metabolism - the sum of the chemical reactions
and energy transformations that take place
within a cell

homeostasis - the tendency of an organism to
maintain a relatively constant internal
environment
.
Characteristics of Living Things

All living things perceive and respond to
stimuli

stimulus - physical or chemical changes in the
internal or external environment of an organism

cells “talk” to each other through cell signaling
via special molecules (such as hormones,
neurotransmitters)

organisms signal state via behavior
.
Characteristics of Living Things

All living things reproduce

All life arises from previous living forms

Reproduction can be asexual (copying):
 Simple
 Many
– cells merely split
unicellular organisms reproduce this way
 Variation
only by mutation in genes
.
Characteristics of Living Things

All living things reproduce

Reproduction can be sexual:
 Sex
= genetic recombination
 Complex,
typically involves fusion of specialized egg
and sperm cells to form a zygote (fertilized egg)
 Genes
provided by parents
 Provides
for variation in offspring
.
•
Explain the characteristics of living
matter to each other. Answer the “Fido”
question (will be described in class).
.

What is the primary way that information
is transferred from one living generation
to the next?

What (in biology) is a Domain?

What are the six kingdoms? (modern
classification)

Why is energy important for life?
.
Chapter 1: The Science of Biology

Scientific Method

Characteristics of living things
 Information
transfer in living
systems

Diversity of Life / classification of living systems

Energy flow in living systems
.
•
Discuss the role of information in life,
and how it is dealt with (on the
molecular level).
.
Organisms Contain an
Information System

Information must be transferred from
one cell generation to the next

In multicellular organisms,
information must also be transferred
from one generation to the next
.
Organisms Contain an
Information System

Cells have an information
system made up of nucleic
acids – specifically: DNA
(deoxyribonucleic acid)




The information is encoded in
regions of DNA called genes, the
units of heredity
Genes are instructions that use a
special, unique code
Instructions are generally for the
production of specific proteins
The nucleic acid code is virtually
identical in all species
.
Organisms Contain an
Information System

Organisms pass on their DNA to the
next generation

Characteristics of each generation
depend upon DNA
.
Organisms Contain an
Information System

Information is also exchanged between
cells

Hormones are chemical signals used for
intercellular signaling

Physical signals may also be used for
intercellular communication
.
•
Discuss the role of information in life,
and how it is dealt with (on the
molecular level).
.
Chapter 1: The Science of Biology

Scientific Method

Characteristics of living things

Information transfer in living systems
 Diversity
of Life / classification of
living systems

Energy flow in living systems
.
•
Explain the binomial system and
taxonomic hierarchy.
•
What is a species name?
•
What do the two words in a species
name represent, and how do you write
them?
•
How will you memorize the hierarchy?
.
The Diversity of Organisms

Biologists use a hierarchical binomial system
for classifying organisms.

about 1.8 million living species have been
identified, likely millions more

Taxonomy - the science of classifying and naming
organisms

Carolus Linnaeus – 18th century Swedish
botanist; developed a system of classification that
is the basis of what is used today

binomial system because a combination of two
names, genus and specific epithet, uniquely
identifies each species
.

Species - basic unit of classification or
taxonomy

if sexual, a group of organisms that can interbreed
and produce fertile offspring

if asexual, grouped based on similarities (DNA
sequence is best)

Genus - a group of closely related species

Species name has two parts (binomial)

Genus and specific epithet (using Latin or Latinized
language)

The specific epithet usually describes something
about the organism, or is based on the name of the
discover
.

Species name has two parts (binomial)

Genus name is always capitalized

specific epithet is never capitalized

The complete species name is always
italicized (or underlined)
 Example:
Homo sapiens or Homo sapiens
 May
abbreviate genus name if used
already and context is clear: H. sapiens
.
Taxonomic classification is hierarchical
•
A group of related genera make up a Family
•
Related families make up an Order
•
Related orders  Class
•
Related classes  Phylum or Division
•
Related phyla or divisions  Kingdom
•
Related kingdoms  Domain, the highest level of
classification in the modern system.
The gold standard for “related” is based on DNA
sequence similarities, but other criteria are used as well
(we don’t have the complete DNA sequence of all known
species)
.
Taxonomic classification is hierarchical
Domain
Kingdom
Phylum
Class
Order
Family
Dashing King Philip came over for great…
Genus
Species
.
•
Explain the binomial system and
taxonomic hierarchy.
•
What is a species name?
•
What do the two words in a species
name represent, and how do you write
them?
•
How will you memorize the hierarchy?
.
•
What are the three domains and six
kingdoms?
•
How do you decide which kingdom to
put a eukaryote into?
.
The most widely accepted
classification
system today includes
three domains and six kingdoms
.
Two domains consist of prokaryotes,
organisms with no true cellular nucleus


Domain Archaea – Kingdom Archaebacteria

bacteria typically found in extreme environments

distinguished from other bacteria mainly by ribosomal
RNA sequence

include methanogens, extreme halophiles, and
extreme thermophiles
Domain Bacteria – Kingdom Eubacteria

very diverse group of bacteria

examples: blue-green algae, Escherichia coli
.
.
Domain Eukarya
eukaryotes, organisms with a discrete cellular
nucleus; divided into four kingdoms
.
Domain Eukarya

Protista

Single celled and simple multicellular
organisms having nuclei

includes protozoa, algae, water molds, and
slime molds

“lump group” for eukaryotes that do not fit in
the other 3 kingdoms within eukarya
.
Domain Eukarya

Protista
NOTE: This kingdom is likely on the way out, to
be replaced by several kingdoms based on
genetic/evolutionary relationships instead
.
Domain Eukarya

Fungi

organisms with cell walls consisting of chitin

mostly multicellular, multi-tissued

includes molds, yeasts, mushrooms

mostly decomposers
.
Domain Eukarya (cont.)

Plantae (plants)

complex multicellular organisms having tissues and
organs

Plant cells have walls containing cellulose

most contain chlorophyll in chloroplasts, and carry
on the process of photosynthesis

Nonvascular (mosses) and vascular (ferns, conifers,
flowering plants)

Mostly producers
NOTE: kingdom is being replaced by Viridiplantae,
which includes green algae
.
Domain Eukarya (cont.)

Plantae (plants)

complex multicellular organisms having tissues and
organs

Plant cells have walls containing cellulose

most contain chlorophyll in chloroplasts, and carry
on the process of photosynthesis

Nonvascular (mosses) and vascular (ferns, conifers,
flowering plants)

Mostly producers
.
Domain Eukarya (cont.)

Plantae (plants)
NOTE: kingdom is being replaced by Viridiplantae,
which includes green algae
.
Domain Eukarya (cont.)

Animalia (animals)
 Complex
multicellular organisms that
depend on other organisms for
nourishment
 Cells
lack walls
 Typically
have organs and organ
systems
 Most
forms are motile
.
•
What are the three domains and six
kingdoms?
•
How do you decide which kingdom to
put a eukaryote into?
.
Chapter 1: The Science of Biology

Scientific Method

Characteristics of living things

Information transfer in living systems

Diversity of Life / classification of living
systems
 Energy
flow in living systems
.
•
What is the importance of energy in
living systems?
•
What are autotrophs and heterotrophs?
.
Life Depends on a
Continuous Input of Energy

All life depends upon
energy

Original source mostly
the sun

Energy flows through
cells, organisms

Energy flows through
ecosystems (the concept
of a food chain or food
web)
.
Energy is used:

To maintain existing cellular structures and
components (replacement of damaged or
worn out materials within the cell)

To produce materials to support growth,
development, and reproduction

To support:

movement, either of cell itself or of materials into
and out of the cell

signaling responses, such as hormone production
and perception, nerve impulses, etc.

other forms of cell work, such as symbiotic
relationships with other organisms, defense against
pathogens
.

Producers (autotrophs) manufacture
their own food from simple materials

usually produce food by the process of
photosynthesis:
Carbon dioxide + Water + light energy
───> Carbohydrate (food) + Oxygen
.

Energy is released from food mostly by
oxidative respiration
Carbohydrate (food) + Oxygen ───>
Carbon dioxide + Water + energy

overall, producers use carbon dioxide
and water and release food and oxygen
.

Consumers (heterotrophs) obtain
energy by eating other organisms

ultimate source of food is producers

use food and oxygen, and release carbon
dioxide and water
.

Decomposers obtain energy by
breaking down the waste products, by
products, and dead bodies of producers
and consumers

Still heterotrophs (ultimate source of food
is producers)

Decomposition recycles nutrients from
dead bodies back to living ones; without
decomposers, living systems would starve
for energy

Decomposers are usually bacteria and
fungi
.
•
What is the importance of energy in
living systems?
•
What are autotrophs and heterotrophs?
.
Themes

learning biology is not just learning a set
of facts and concepts; you need to
organize that information

watch for the recurrence of certain
themes that come up repeatedly in
biology (major examples on next slides)

in addition, an awareness of the process
of scientific inquiry and the application of
science (technology) are important
aspects of any study of biology
.
Figure
1.3
.
Figure
1.3
.
Themes

The cell

Information management

heritable information

regulation

interaction with the environment

Energy management

Structure and function

Unity and diversity

Emergent properties

Evolution – the core unifying theme that explains
much of the observations connected with the other
themes
.