1. WARM UP!
Write down ONE safety rule
What is a hypothesis?

2. Today’s Objectives: We will:
compare the different types of investigations we will be doing
2. review the scientific method/variables
3. discussing accuracy vs. precision

3. Introduction to Biology
Scientific method
Graphing

4. BIOLOGY = The study of life
Etymology – using parts of words (prefixes and suffixes) to figure out what the word means.
BIO = Life
OLOGY = the study of

5. There are different ways to solve problems.
Scientists use 3 different types of investigations to solve problems.
1. Descriptive Investigations
2. Comparative Investigations
3. Experimental Investigations

6. Descriptive Investigation
With a partner, in the box provided describe what you think descriptive sounds like or means.
Used to observe and describe
Draw a line to the Descriptive investigation.

7. Comparative Investigation
In the box provided, write what you think comparative sounds like or means.
Used to collect data and make a comparison.
Draw a line to the Comparative investigation.

8. Experimental Investigation
What does experimental sound like or mean?
Used to manipulate or change variables to gather evidence to support or refute a relationship or hypothesis.
Draw a line to the experimental investigation.
These are the types of investigations where scientists use the scientific method.

9. Scientific Method (6 steps)
Define the PROBLEM – usually a question.
Which type of fertilizer causes the most growth in tomato plants?

10. Do RESEARCH – provides background information.
The scientist researched other experiments to see the effects of fertilizer on tomato plants.

11. ? Create a HYPOTHESIS – Make a prediction.
MUST me testable and measureable.
If 1 oz. of Miracle-Gro fertilizer is applied to the tomato plants every other day for 14 days, the plants will show the most growth when compared to plants given other fertilizers. ?

12. Which hypothesis is better?
If I study for my biology test, I will get a good grade.
If I study biology every night for 30 minutes, I will earn an A on my biology test.

13. Which hypothesis is better?
If I water my yard for 30 minutes a day, 5 days a week, my yard will grow.
If I water my yard, the grass will grow.

14. Which hypothesis is better?
Sugar kills worms.
If I add 5 mL of sugar water to the worm, it will kill it.

15. Perform an EXPERIMENT – this tests your hypothesis
He tests the fertilizers called Scott’s Liquid Grow, Miracle-Gro, and Fertilome Super Grow. He also tests one group of plants that do not receive any fertilizer. All plants are given the same amount of water, sunlight and potting soil. The scientist measures the height of the plants every 2 days for 14 days.

16. GATHER and ANALYZE DATA – use data from your experiment
USE DATA TABLES!

17. Form a CONCLUSION – based on the data from the experiment.
Based on the data provided, it has been shown that applying Miracle Gro increased the growth of the plant more than the other fertilizers.

18. Controlled Experiment – only 1 variable is being tested at a time

19. 1. Variable – factor in an experiment that can change
Ex: temperature, time, size, amount or kind of material

20. Manipulated = Independent = Experimental
2. Variable that is deliberately changed –manipulated or independent variable
Typically the manipulated or independent variable can also be considered as the experimental.
Manipulated = Independent = Experimental

21. Responding = Dependent
3. Variable that changes in response to or because of the manipulated variable – responding or dependent variable
Responding = Dependent

22. 4. Experimental group – contains the variable being tested
Ex. The tomato plants with the fertilizer
5. Control group – does not contain the experimental variable
Ex. The tomato plants without fertilizer

23. FACTORS THAT SCIENTISTS PURPOSELY CHANGE:
MIX – Manipulating variable, Independent variable, X axis
FACTORS THAT MAY CHANGE BECAUSE OF THE MANIPULATED VARIABLE
DRY – Dependent variable, Responding variable, Y axis

24. What could the experimental variable be?
The amount of light exposure

25. Example:
A scientist designs an experiment to see which kind of fertilizer causes the most growth in tomato plants. He tests Scott’s Liquid Grow, Miracle-Gro, and Fertilome Super Grow. He also tests one group of plants that do not receive any fertilizer. All plants are given the same amount of water, sunlight and potting soil. The scientist measures the height of the plants every 2 days for 14 days.

26. Experimental variable = kind of fertilizer
Control group = group that received no fertilizer
Manipulated (independent) variable = kinds of fertilizer
Responding (dependent) variable = plant height

27. When gathering and analyzing data from an experiment:
Data should be gathered from large sample sizes in order to show better results.
Ex: use many tomato plants (100+) when testing for fertilizers

28. Ex: Hitting close to or on the bulls eye of a target
ACCURACY - The closeness of a measurement to the true value of what is being measured
Ex: Hitting close to or on the bulls eye of a target

29. Ex: Hitting close to or on the bulls eye of a target multiple times
PRECISION/PRECISE - exact or repeated measurements very close in value
Ex: Hitting close to or on the bulls eye of a target multiple times

32. Form a conclusion based on the data from the experiment
If data supports hypothesis – repeat the experiment for verification
A hypothesis tested and confirmed often enough that it is unlikely to be disproved and becomes a theory
If data does not support hypothesis – refine or change the experiment, then repeat experiment

33. Once an experiment is completed, the data is put in to a data table and a graph can be created.
EXPERIMENT DATA TABLE GRAPH

34. Organizing Lab Data Experiment Graph Tomato Plant Growth Date
Plant A Height
Plant B Height

35. Temperatures In NY City
Data Table
Temperatures In NY City
Day
Temperature 1
43° F 2
53° F 3
50° F 4
57° F 5
59° F 6
67° F
What goes on the X Axis? Day What goes on the Y Axis? Temperature
On your notes draw a line to the correct graph

36. Organizing Lab data
Line Graph

37. Bar Graph

38. Pie Graph

39. Variables on the graph
D = Dependent variable or
R = Responding variable on
Y = Y axis
M I X
Manipulated variable or Independent variable on the X axis

40. Good Graphs Label axes – be specific, use units time – hour, minutes
weight – pounds, grams
2. Numbers on axes must be in even increments and evenly spaced
2, 4, 6, 8, 10
5, 10, 15, 20
1, 5, 7, 10, WRONG!

42. FYI
SAFETY Quiz TOMORROW!