Bio 101: Biological Principles
Natasha Anwar
Lecture 1
Introduction
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The course
 Biology – the science of life
 Scientific Method
The Course
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Core – 4 units
30 lectures – Tues & Thurs, 17.30 – 18.45
Fri, 17.30 – 18.20
Sayeed Saigol Auditorium
11 topics
Final grade will be calculated as follows:
Quizzes
Assignments
Mid-term exam
Term paper
Final Exam
25%
5%
25%
10%
35%
Attendance
Understanding
Student Assessment
Quizzes – random, 15 min test
 Assignments – twice a week, 3 students
selected at random to present their
assignment.
 Mid-term exam – 1 hr, short answer
questions.
 Term Paper
 Final Exam – 3 hr, short essay questions
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Plagiarize
“To use another persons idea or part of their
work and pretend that it is your own”,
Cambridge International Dictionary of English
Biology – the science of life
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bios, life; logos, knowledge
 The study of living organisms, and the
biological processes that enable them to
function and survive.
Reductionist Principle
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The study of life is complex
so broken down into
compartments
 Within a cell
 Among cells in an organ
 Among the organ systems
in an organism
 Between organisms and the
environment
 Among individuals in a
population
 Between species
Chemicals
Cells
Tissues
Organs
Systems
Organism
Population
Community
Ecosystem
Microbiology
Virology
Bacteriology
Mycology
Botany
plants
Anatomy
Gross structure
Physiology
gross function
Cell biology
Biology
Zoology
Genetics
animals
Inheritance
cells
Biochemistry
/Molecular Biology
molecules
Living Organisms
Are capable of :
Growth and development
 Metabolism
 Homeostatis
 Movement
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Detect and react to stimuli
 Reproduction
 Composed of cells
 Contain DNA
 Adaptation and evolution
How were biological
principles discovered?
The Scientific Method
Law
Interpretation
theory
results
controlled experiments
Hypothesis
qualitative
data
accept
modify
reject
quantitative
Observation
Facts
Biological Science, 3rd Edition
pp 951
Example
Observation: There are always so many
flies at the butchers shop, especially
around rotting meat
Example
Question: Where do flies in the shop come
from, and does rotting meat produce or turn
into the flies?
Hypothesis: Rotten meat dose not turn into
flies. Only flies can make more flies.
Prediction: If meat cannot make more flies,
rotting meat sealed into a container should
not produce flies or maggots.
Example
Experimental Testing:
1. Wide mouth jars each containing a piece of meat
opened to various degrees.
2. Control group – a jar of meat set out without a
lid.
3. Experimental groups – one group of jars were
sealed with lids another group with gauze.
4. Replication – several jars were included in each
group.
5. Presence and absence of flies and maggots seen
in each jar were recorded.
Example
Data:
 In control group – flies entered jar, maggots seen
later and then more flies seen on the meat.
 In gauze covered jars – no flies in the jar, but on
and around the gauze. Later maggots seen on the
meat.
 In the sealed jars – no maggots or flies seen on the
meat.
Example
Conclusion:
 Only flies can make more flies.
 Uncovered jars flies came and laid eggs on
the meat. Maggots hatched from the eggs
and grew into adult flies.
 Adult flies laid eggs on the gauze, eggs or
maggots dropped through gauze onto meat.
Incomplete Research
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An example of a scientific conclusions based on
insufficient scientific method occurred in the field of breast
cancer research.
Breast cancer is caused when normal cells change and
produce a tumour. In a study published in the New
England Journal of Medicine (336, 1269 (1997)), scientists
from Norway studied the incidence of breast cancer in
25,624 women.
Participants gave details about their height, weight, diets,
and exercise habits. The results showed an over all
reduction of breast cancer by 37% for women who
exercise regularly. Women who are lean and exercise at
least 4 hrs per week showed the lowest incidence.
Does Exercise Prevent
Breast Cancer?
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Many newspapers picked up on the data with headlines
stating that exercise prevents cancer
An editorial in the same journal put the results in proper
perspective.
Women who exercise regularly have higher levels of
education and income, smoke less, drink less alcohol, and
consume fewer calories and less fat.
Establishing a casual pathway between reduced breast
cancer and physical activity will require exploration for
biologic mechanisms and confirmation with clinical
experiments.
Quote:
“ The formulation of a problem is often more essential than its
solution, which may mainly be a matter of mathematical or
experimental skill. To raise new questions, new possibilities, to
regard old problems from a new angle requires creative
imagination and marks real advance in science ”
Albert Einstein