Biology IBiology IMr. NettlesMr. Nettles

Agenda- Wednesday, Agenda- Wednesday, August 17, 2011August 17, 2011

1. Warm Up – 5 min1. Warm Up – 5 min

2. Daily Lesson – 25 min2. Daily Lesson – 25 min

3. Wrap Up – 5 min3. Wrap Up – 5 min

4. Homework/Practice – 25 min 4. Homework/Practice – 25 min

Warm-UpWarm-Up

1.1. Write one quantitative and one Write one quantitative and one qualitative observation about qualitative observation about yourself.yourself.

2.2. Which step of the scientific method Which step of the scientific method involves making table and graphs?involves making table and graphs?

3.3. Which three steps of the scientific Which three steps of the scientific method come after “Making method come after “Making Observations”?Observations”?

Today’s Today’s ObjectivesObjectives

I will understand the steps I will understand the steps involved in the scientific method.involved in the scientific method.

I will understand the parts of an I will understand the parts of an experiment or scientific experiment or scientific investigation.investigation.

I will understand the meanings of I will understand the meanings of control, hypothesis, independent control, hypothesis, independent variable, and dependent variablevariable, and dependent variable

HypothesisHypothesis

The The hypothesishypothesis is an is an educated educated guessguess about the relationship about the relationship between the independent and between the independent and dependent variables.dependent variables.

A hypothesis is usually written A hypothesis is usually written as an IF/THEN statement.as an IF/THEN statement.

What is Variable?What is Variable?

A A VARIABLEVARIABLE is a factor in an is a factor in an experiment that can experiment that can change.change.

There are two types of There are two types of variables in an experiment: variables in an experiment: INDEPENDENT variable INDEPENDENT variable and and the the DEPENDENT variable.DEPENDENT variable.

Independent Independent VariableVariable

The The independent or independent or manipulating variable manipulating variable is is the factor that is the factor that is intentionally changedintentionally changed by the person doing the by the person doing the experiment.experiment.

Dependent Dependent VariableVariable

The The dependent or dependent or responding variable responding variable is is the factor that may the factor that may change because of change because of changes made to the changes made to the independent variable.independent variable.

Controls or Controls or ConstantsConstants

CONTROLS or CONSTANTS CONTROLS or CONSTANTS are factors that scientists are factors that scientists purposely purposely keep the SAME keep the SAME in in an experiment.an experiment.

The The purpose of a control purpose of a control is is to ELIMINATE OUTSIDE to ELIMINATE OUTSIDE FACTORS that may throw off FACTORS that may throw off the experiment.the experiment.

Critical ThinkingCritical Thinking

What two steps of the What two steps of the scientific method have we scientific method have we been focusing on today?been focusing on today?

Answer: Answer: “Form a “Form a Hypothesis” and “Test Hypothesis” and “Test your Hypothesis your Hypothesis /Experiment”/Experiment”

Quick Exercise:Quick Exercise:

Write a hypothesis about your Write a hypothesis about your grade in this class using an grade in this class using an if/then statement.if/then statement.

Example: If I study an hour every Example: If I study an hour every night, then I will get an 80% or night, then I will get an 80% or higher on all Unit Assessments.higher on all Unit Assessments.

PRACTICEPRACTICE

Situation: Juan is trying to grow Situation: Juan is trying to grow plants.plants.

Problem: Will Juan’s plants Problem: Will Juan’s plants grow better if he puts them in grow better if he puts them in the sun?the sun?

Hypothesis: If Juan puts his Hypothesis: If Juan puts his plants in the sun, then they will plants in the sun, then they will grow better.grow better.

What is the purpose of a What is the purpose of a control?control?

A.A. A control functions to make sure that A control functions to make sure that everyone follows the directions of an everyone follows the directions of an experiment.experiment.

B.B. A control functions to eliminate the effect of A control functions to eliminate the effect of outside variables on an experiment.outside variables on an experiment.

C.C. A control functions to increase variability in A control functions to increase variability in an experiment.an experiment.

D.D. A control functions to manage the outcome of A control functions to manage the outcome of an experiment.an experiment.

Michael wants to know if mice like to Michael wants to know if mice like to eat cheese or peanut butter. eat cheese or peanut butter.

He gets 6 white mice that are similar He gets 6 white mice that are similar in size and age. in size and age.

He places one mouse at a time in the He places one mouse at a time in the center of a large cage. center of a large cage.

At one end of the cage is a small plate At one end of the cage is a small plate filled with peanut butter and at the filled with peanut butter and at the opposite end of the cage is a small opposite end of the cage is a small plate filled with cheese.plate filled with cheese.

Michael observes each mouse for 15 Michael observes each mouse for 15 minutes and records the data. minutes and records the data.

1.1.What is the problem?What is the problem?

2.2.What is your hypothesis?What is your hypothesis?

3.3.What is the independent What is the independent variable and dependent variable and dependent variable in this experiment?variable in this experiment?

4.4.What controls would be What controls would be needed? needed?

Controls needed:Controls needed:

Make sure mice are Make sure mice are getting the same amount getting the same amount of water, light, heat, of water, light, heat, amount of cheese, color of amount of cheese, color of cheese, different colored cheese, different colored mice, different size cages, mice, different size cages, etc.etc.

Wrap-UpWrap-Up

1.1. What is a hypothesis and what What is a hypothesis and what type of statement is it usually type of statement is it usually written as?written as?

2.2. What is the purpose of a What is the purpose of a control?control?

3.3. In your own words, explain what In your own words, explain what independent variable and independent variable and dependent variable mean?dependent variable mean?