NR 215 Plant Biology: Course Overview and Introduction To The Scientific Method

NR 215
PLANT BIOLOGY
Lecture 1:
Course Overview and Introduction to the Scientific Method
Housekeeping
 Lectures: Keith Hautala (KBM Forestry)
 B.Sc. (Env) – University of Guelph
 M.Sc.F – Lakehead University
 Labs: Caleigh Sinclair
 “Office hours”
 I’m on campus 2 days/week
 Can meet before or after class
 Or email questions or to setup a meeting time
 khautala@kbm.on.ca
 Class intros and biology backgrounds

Course Overview
 This is a “foundation” course
 To be able to work effectively
with living organisms, one
must have a basic
understanding of biology
 On this foundation, an
understanding of growth and
reproduction can be based
 Need to know specifically how
and why forest plants survive,
grow and reproduce
Course Overview (con’t)
 Introduction to scientific inquiry (theories,
hypothesis testing)
 Basic biology of plants and trees from the cellular
level to the ecosystem
 Understanding of metabolic process in plants
such as photosynthesis and respiration
 Plant diversity, and the life cycles of conifers
(gymnosperms) and hardwoods (angiosperms),
will be explored
 The structure and function of non-woody and
woody plant tissues and organs will be examined
along with tree growth and genetics
Course Overview (con’t)
 Marking Scheme:
 Lab and Quizzes 50% (-10%/day late)
 Mid-term Exam 20%
 Final Exam 30%
 While I will not be checking, attendance is

your responsibility.
 Missing lectures and labs will lower your grade
in this class.
Lecture Overview
 Cells -> Anatomy -> Physiology
 Textbook:
 Stern, Kingsley R. Introductory Plant Biology. 12 th
Edition. McGraw-Hill, N.Y., New York. ISBN 0-07-
310175-3.
 Blackboard
 Course Documents will have lecture presentation
and labs by week
Lab Overview (McIntyre 210)
 A more in-depth presentation of principles
presented in lectures
 Hands on exploration of plant structures
 Quizzes (~3) on terminology
 Lab assignments will be posted on Blackboard
prior to lab
 It is your responsibility to bring lab printout to
class
 Assignments are due at the beginning of next lab
 Note: most lab assignments will be completed in-class
 Labs will be graded at -10% per day late
Importance of Plants
 Dependence of other life:

1. Photosynthesis
2. Food and food chain
(Three species of grasses
- rice, wheat, and corn -
are the most important
food plants)
3. Industrial uses (e.g. wood,
cotton, coal, oils, etc.)
4. Medicinal (>1,000
medicinal plants)
 Other uses or things plants
provide?
Plant Study: “Cinderella of the biological sciences”
 Plant Anatomy
 Internal structure of plants
 Plant Physiology
 Plant function (e.g. growth, movement of
material, etc)
 Plant Taxonomy
 Describing, naming and classifying
 Plant Genetics
 Heredity, breeding
 Cell Biology
 Cell structure and funciton
Scientific Method: A Cyclical Process
Overview
 If a particular hypothesis/premise is true
 And “X” experiment is done
 Then one should expect (prediction) a certain result.
 This involves the use of “if-then” logic
 For example, if my hypothesis that my throat is
sore because I did too much screaming at the ball
game is true and if a doctor examines my vocal
cords, then (s)he should be able to observe that
they are inflamed, and as the inflammation heals,
the sore throat should go away.
History of the Scientific Method
 Aristotle (384 BC – 322 BC) formulated
what may be the beginning the scientific
method
 He provided one of the key ingredients of
scientific tradition: Empiricism
 Empiricism = a theory of knowledge that asserts
that knowledge arises from sense experience
(e.g. the mind is a “blank slate” at birth)
 Empiricism contrasts with “Innatism” which is a
belief that the mind is born with ideas/knowledge
 For Aristotle, universal truths could be known
from particular things via induction (see
“inductive reasoning” in a few slides)
 It goes back further than Roger Bacon,
Frances Bacon, Galileo Galilei, and
Isaac Newton
 Alhazen (965 (Basra, Iraq) - 1039
(Cairo, Egypt))
 The “father of modern optics”
 Most historians consider him to be the
pioneer of the modern scientific method
 Rigorous experimental methods of
controlled testing to verify hypotheses

 Very similar to the modern scientific
method
 Roger Bacon (1214-1294), drawing on the writings of
Muslim scientists, described a repeating cycle of
observation, hypothesis, experimentation, and verification
 Francis Bacon (1561-1626) is famous for explaining his
method in Novum Organum (1622). He is widely mentioned
in literature for his contribution to the scientific method
 In our modern culture, Galileo (1564-1642) is generally
credited with being the father of the scientific method
 “Even while Bacon was philosophizing, the true method was being
practiced by Galileo, who, with a combination of observation,
hypothesis, mathematical deduction and confirmatory experiment
founded the science of dynamics.” - Encyclopedia Britannica
 Rene Descartes (1596-1650) Discourse on Method (1637)
is also a significant contribution to the development of the
scientific method
Hypothesis and Theory
 Hypothesis = “A tentative explanation for
an observation, phenomenon, or
scientific problem that can be tested by
further investigation.”
 Inductive reasoning
 Goes from a set of specific observations to general
conclusions: I observed cells in x, y, and z organisms,
therefore all animals have cells.
 Deductive reasoning
 Goes from general to specific. From general premises, a
scientist would extrapolate to specific results: if all
organisms have cells and humans are organisms, then
humans should have cells. This is a prediction about a
specific case based on the general premises.
 Hypothesis vs. Theory vs. Law

 Theory implies a greater range of evidence and greater
likelihood of truth (e.g. the theory of evolution)
 Law implies a statement of order and relation in nature
that has been found to be invariable under the same
conditions (e.g. the law of gravitation)
Hypothesis Formation
 Observation: Have you ever noticed if you place a plant near
a window, that after a while, the plant grows or leans toward
the window?
 Hypothesis: What reasons or factors can you list that might

cause a plant to lean or grow toward a window? For example,
do you think that:
1. Plants like Microsoft products
2. Plants catch a virus from the window, and that makes them
lean toward the window
3. Plants respond to the glass from which they absorb some
needed nutrient
4. Plants respond to the light which they need to make their food
5. Plants respond to fresh air leaking in the window
6. Plants are attracted to the plants outside the window
Predictions
 A prediction is the expected results if the
hypothesis and other underlying assumptions and
principles are true and an experiment is done to
test that hypothesis
 Examples:
 If fertilizer makes a plant grow faster, then seedlings
planted with fertilizer will be taller than the ones
planted without fertilizer
 In physics, if Newton’s Theory of Motion is true and
certain “unexplained” measurements pointing to the
possibility of another planet are correct, then if I point
my telescope to the specific position that I calculate, I
should be able to discover/observe that new planet
(this is the way Neptune was discovered in 1846)
Predictions: “Hypothesis Testing”
 Hypothesis:
 A statement which can be proven false
 Null hypothesis (Ho) = “There is no difference”
 Alternative hypothesis (Ha) = “There is a difference…”
 In statistical testing, we try to “reject the null
hypothesis”
 If the null hypothesis is false, it is likely that our
alternative hypothesis is true
 “False” – there is only a small probability that the
results we observed could have occurred by
chance
Experiment
 Scientists perform experiments to see if the
predicted results are obtained. If the expected
results are obtained, that supports (but does not
prove) the hypothesis
 The experiment must be a controlled experiment:
 The scientist must contrast an “experimental group”
with a “control group”
 The two groups are treated EXACTLY alike except for
the ONE variable being tested
 Sometimes several experimental groups may be used
 For example, in an experiment to test the effects of day
length on plant flowering, one could compare
normal/natural day length (the control group) to several
variations (the experimental groups)
Observations
 In a “cause and effect” relationship, what you
observe is the effect (the hypotheses are the
possible causes).
 Science often begins with observations –

taking data on what you see, hear or smell
 Data = the information gathered from

observations
 Qualitative data = descriptive
 Quantitative data = numbers
Bias
 Sometimes our expectations can determine the outcome of
an experiment (e.g. Experimenting with new foods)
 Presented with a roasted grub (considered a delicacy in some
societies), we generally expect that it will taste awful
 If we are brave enough to try it, it may taste awful on the first bite, even
though it actually tastes like cashews…our expectations prejudice our
observations
 In a scientific investigation, it is possible to influence our
observations by tampering with the experimental controls or
biasing our observations
 E.g. Moving a specific group of tomato seeds to a warmer
location after the experiment has begun because we expect or
hope that this specific group of seeds will germinate better
 Biased observations are usually made unconsciously by the
observer and are rarely deliberate attempts to misrepresent
the data
 E.g. “Rounding up” close height measurements in a specific
group of plants
Correlation vs. Causation
 I can prove that the likelihood of dying from cancer is directly
related to the number of shoes a person owns
 Why does it not make sense to go home and get rid of all of your shoes?
Reading
 REMINDER: No Labs This Week
 Stern. Chapter 1.

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NR 215

 Class intros and biology backgrounds

 While I will not be checking, attendance is

 Dependence of other life:

controlled testing to verify hypotheses

 Hypothesis vs. Theory vs. Law

 Hypothesis: What reasons or factors can you list that might

 Science often begins with observations –

 Data = the information gathered from

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