1. Biology
“The study of life”

2. Living things are ORGANIZED
All made of the same collection of atoms, but we are organized as…
molecules
proteins, fats, carbohydrates, nucleic acids
proteins
carbohydrates
DNA

3. Living things are ORGANIZED
All made of the same collection of atoms and molecules, but we are organized as…
organelles & cells
plant cells & animal cells
plant cell
animal cell

4. Living things are ORGANIZED
All made of the same collection of chemicals, but we are organized as…
organs & organ systems
respiratory, circulatory, digestive, etc.

5. Living Creatures Grow and Develop

6. Even single-celled organisms!

7. Living creatures REPRODUCE
Asexual – 1 parent. Offspring are identical to parent.
Sexual – 2 parents. Genes are mixed.
Make the next generation

8. Living creatures use ENERGY
Metabolism
all the reactions your body performs to make & use energy
eating & digestion & elimination of waste
synthesis = building
Photosynthesis = plants use light energy to build sugars
cellular respiration = breaking down sugar (stored chemical energy) into ATP (useable energy)

9. Living creatures RESPOND
Respond to internal changes (stimuli)
Homeostasis
maintaining balanced conditions inside the body
Respond to external changes (stimuli)

10. Living Things ADAPT
change over time. Genetic changes in a population are passed down over generations.
Catch food
Deter predator
Find a mate

11. Experimentation in Biology
The Methods of Science

12. Methods of Science
Using rational thinking and experimentation to answer questions/ solve problems.
Note: “Scientific methods” are not a series of steps that must be followed in order. They are guidelines for experimentation to ensure useful, meaningful data.

13. Methods of Science Question
Experimentation begins with a question/problem. Must be testable, falsifiable and measurable.
Good example: Will taking drug X reduce the risk of heart attacks in humans?
Bad example: Was Albert Einstein the most brilliant scientist who ever lived?

14. Good Question? A. Will breaking a mirror bring bad luck?
B. Are dogs better than cats?
C. Do heavy objects fall faster than light objects?
D. Will adding fertilizer help plants grow?

15. Methods of Science Hypothesis
Must be specific and explain what you expect to see.
Usually and If, then….. Statement.
Good example: If dropped from the same height, heavy and light objects will take the same amount of time to fall to the ground.
Bad example: Yes. They will fall the same.

16. Design a hypothesis…
Question: How will a goldfish’s rate of respiration be affected as its water is heated from 50C to 200C?
Hypothesis:

17. Controlled Experiments
Developing a Procedure  
Controlled experiments compare 2 or more groups. The control group is left alone, under normal conditions. The experimental group is altered, it is subject to your changing variable.
Only one difference exists between the 2 groups, all other factors remain the same. These are called controls.

18. Controlled Experiments
 Independent Variable: The condition that you (the experimenter) are testing. This is the one difference between the control and experimental groups.
Example 1: Type of heart attack medicine being taken
Example 2: Water temperature for goldfish
Dependent Variable: Changes because of the IV. This is usually what you will be measuring, your data.
Example 1: Incidence of heart attacks in patients
Example 2: Goldfish respiration rate
By including only an IV in your experiment (1 difference between groups), you can be sure that any change in the DV is the result of the IV.

19. Quick Quiz!!
Question: Does eating breakfast improve student test scores?
Develop a hypothesis for this problem
Design a controlled experiment to test your hypothesis
What is the IV of your experiment? What is the DV?
What variables must you control when running this experiment?

20. Methods of Science Reporting Your Results
Date Tables: Help Organize Data
Graphs: Help Interpret Data

21. Data Tables
Column for DV (units)
Multiple Trials
Column for derived quantity
Column for IV (units)
Set up a table: How does length of time dipped in water affect the height the water will travel up a strip of paper towel?

22. Data Tables 1 2 3 Average height (mm) Time paper towel submerged (sec)
Height liquid rose in towel (mm)
Trials
Average height (mm)
Time paper towel submerged (sec)

23. Showing patterns & trends
Graphing Your Data
Showing patterns & trends

24. 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

25. 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

26. 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

27. 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

28. Making pictures out of data
Graphs
line graphs
graphing data that shows continuous change
bar graphs (or histograms)
graphing data that is in disconnected groups
Which should I use?

29. Which type of graph?
How does temperature affect the rate of cricket chirps?
How quickly do sound waves travel through different media?
Which brand of paper towel absorbs the most water in a 5-s period?
Under which color of light do plants grow most quickly?

30. Plot Your Graph, Summarize Trends
Linear Relationship
Exponential
Random, no trend

31. Line of Best Fit