Introduction: Themes in the study of life

1. Chapter 1 Introduction: Themes in the study of life

2. AP Biology • Big Idea 1 - Evolution • Constant theme in Biology • Big Idea 2 - Energy • Constantly moving through living organisms • Big Idea 3 - Information • Store, Retrieve, Transmit, Respond • Big Idea 4 - Systems • Interworkings of complex properties

3. Emergent Properties • New properties become present at each new level • Due arrangement as complexity increases

4. Reductionism • Understanding complex systems is difficult • Cannot understand full function with just single parts • Understanding complex systems requires dissection • Break complex systems to simpler components

5. Energy • The ability to do work • Transfers-never disappears • Describe how sunlight gets to us

6. Structure and Function • Form dictates function • Wings versus hands • Leaf shape • Muscle design

7. Cells • Basic unit of life • Common characteristics • Membranes • DNA • Prokaryotic vs. Eukaryotic

8. DNA • The information of life • DNA • Chromosomes • Genes • Ability to be copied • A,T, C, G • Instructions for proteins

9. Feedback • Coordination of cellular processes • Negative vs. Positive • Negative • Most common • Set range • Positive • Enhances

10. Evolution • The reason for life • Diversity of life • Major underlying theme of all of biology • Always asking why does something do something? • Requires organization

11. Natural Selection • Charles Darwin • On the Origin of Species by Means of Natural Selection • Existing species come previous species • Descent with modification • Natural Selection

12. Study of Science • Science – a way of knowing, understanding • Process • Observations • Hypothesize • Testing • Requires flexibility

13. Designing Experiments • Controlled experiments • Experimental and Control groups are kept under same variables apart from the factor under study • Ex. Drug effects • Variables, Controls, and Constants • Independent/Dependent Variables

14. Statistical Analysis • Use to show relationships of the data and the variables • Mean (average) • Standard Deviation (SD) • Chi square (p) • Graphing • Shows patterns and trends

15. Mathematical Determinations • Average Chi Square • Standard Deviation

16. Chi Square test • Difficult to understand • Why use: • Is there a difference between what you found and what should be found? • Is the data organized into categories? • Does the data add up to more than 20? • Does the expected data for each category exceed four?

17. Chi Square test • Determine Null hypothesis • The number of theoretical values is the same as the expected values (1:1 male to female) • Determine the expected value (usually done by determining an average) • Use Chi square to determine the significance of disproving the null hypothesis

18. Chi Square test • 5 Guys Burgers and Fries will be a benefit to the whole community • 1 – strongly agree • 2 – Agree • 3 – Neutral • 4 – Disagree • 5 – Strongly disagree • Sample size: 20

19. Chi Square test Null hypothesis: There is no significant difference between the categories of the local person and frequency of negative responses

20. Chi Square test

21. Chi Square test

22. Chi Square test • Results: • Negative responses: 10.4 • Degrees of freedom (df = n-1) • df = 5 – 1 = 4 • Use critical values table to determine significance • Significance tells you how confidently we disprove our null hypothesis

23. Chi Square table Degrees of Freedom P value

24. Chi Square test • x2 = 10.4 • Our degrees of freedom is 4 • To reject the null hypothesis our chi square value must be greater than the 0.05 value (Ours = 10.4, df 4 = 9.49) • REJECT THE NULL HYPOTHESIS – There is a difference between the peoples responses

25. Chi Square Example 1 • European Crossbills – expect a 1:1 ratio • Goth (1992) observed 1752 right-billed and 1895 left-billed birds • Is there a difference between what Groth observed and what should happen (expected)?

26. Types of data (information) • Variables • what you measure in an experiment • dependent variable • measured variable • unpredictable change: we don’t know how it will change until we do the experiment • Y-axis • independent variable • manipulated variable • predictable change: it only changes because we chose how it would change • X-axis The effect of _____________on _____________ INDEPENDENT DEPENDENT

27. Examples of experiments 1 • How does fertilizer affect the growth rate of plants? • we set up an experiment testing different amounts of fertilizer on different plants & measuring the growth (height) of the plants: • dependent variable (Y-axis)? • height of plants • independent variable (X-axis)? • amount of fertilizer The effect of _____________on _____________ Amount of Fertilizer Height of Plants

28. Examples of experiments 2 • How does exercise affect heart rate of 10th grade student? • we set up an experiment testing different lengths of time of exercise (minutes) on the heart rate of students: • dependent variable (Y-axis)? • heart rate • independent variable (X-axis)? • minutes of exercise The effect of _____________on _____________ Exercise Heart Rate

29. Examples of experiments 3 • What’s the favorite drink of students? • we set up an experiment surveying students and asking which is their favorite drink : • dependent variable (Y-axis)? • number of students • independent variable (X-axis)? • type of drink The effect of _____________on _____________ Type of Drink How many students chose it

30. Making pictures out of data How’s a critterto choose? • Graphs • line graphs • graphing data that shows continuous change • bar graphs (or histograms) • graphing data that is in disconnected groups

31. 10 20 30 15 25 0 5 0 1500 1000 2500 2000 500 1200 How does elevation affect temperature? Line graph! 18 temperature 1200 ft? elevation

32. 0 2 4 6 1 3 5 Gatorade water Pepsi Coke tea Which drink do you like best? Bar graph! number of students Red Bull? RB RB type of drink