Bio 101: Biological Principles

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Bio 101 Biological Principles

• Natasha Anwar

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Lecture 1Introduction

• The course
• Biology the science of life
• Scientific Method

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The Course

• 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 25
• Assignments 5
• Mid-term exam 25
• Term paper 10
• Final Exam 35

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Student Assessment
Attendance Understanding

• 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

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Biology the science of life

• bios, life logos, knowledge
• The study of living organisms, and the biological
  processes that enable them to function and
  survive.

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Reductionist Principle

• 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
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Anatomy Gross structure
Microbiology Virology Bacteriology Mycology
Physiology gross function
Biology
Cell biology cells
Botany plants
Biochemistry /Molecular Biology molecules
Genetics Inheritance
Zoology animals
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Living Organisms

• Are capable of -
• Growth and development
• Metabolism
• Homeostatis
• Movement

• Detect and react to stimuli
• Reproduction
• Composed of cells
• Contain DNA
• Adaptation and evolution

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How were biological principles discovered?
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The Scientific Method
Law
Interpretation
theory
results
controlled experiments
accept
modify
Hypothesis
reject
qualitative
quantitative
data
Observation
Biological Science, 3rd Edition pp 951
Facts
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Example

• Observation There are always so many flies at
  the butchers shop, especially around rotting meat

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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.

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Example

• Experimental Testing
• Wide mouth jars each containing a piece of meat
  opened to various degrees.
• Control group a jar of meat set out without a
  lid.
• Experimental groups one group of jars were
  sealed with lids another group with gauze.
• Replication several jars were included in each
  group.
• Presence and absence of flies and maggots seen in
  each jar were recorded.

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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.

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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.

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Incomplete Research

• 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.

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Does Exercise Prevent Breast Cancer?

• 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.

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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