Bio 101: Biological Principles

1. Bio 101: BiologicalPrinciples Natasha Anwar

2. Lecture 1Introduction • The course • Biology – the science of life • Scientific Method

3. 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%

4. 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

5. Plagiarize “To use another persons idea or part of their work and pretend that it is your own”, Cambridge International Dictionary of English

6. 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.

7. 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

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

9. Are capable of :- Growth and development Metabolism Homeostatis Movement Detect and react to stimuli Reproduction Composed of cells Contain DNA Adaptation and evolution Living Organisms

10. How were biological principles discovered?

11. The Scientific Method Law Interpretation theory results controlled experiments accept modify Hypothesis reject qualitative quantitative data Observation Biological Science, 3rd Edition pp 951 Facts

12. Example Observation: There are always so many flies at the butchers shop, especially around rotting meat

13. 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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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