I-N-D-E-P-E-N-D-E-N-T variables, dependent variables, and constants

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I-N-D-E-P-E-N-D-E-N-T variables, dependent variables, and constants. Catalyst: What is a hypertonic solution? Let’s say you put a cell in a hypotonic solution. What will happen to it?. Team Points. Team 118 Team 231 Team 329 Team 425 Team 523 Team 631 Team 717 Team 816. - PowerPoint PPT Presentation

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I-N-D-E-P-E-N-D-E-N-T variables, dependent variables, and constants

Catalyst: What is a hypertonic solution?

Let’s say you put a cell in a hypotonic solution. What will happen to it?

Team Points

Team 1 18 Team 2 31 Team 3 29 Team 4 25 Team 5 23 Team 6 31 Team 7 17 Team 8 16

Objectives

By the end of today, SWBAT… Identify independent, dependent, and controlled variables in a scientific experiment

Create a model of osmosis with eggs

Experimentation

Key Point #1: A proper experiment always has an independent variable, dependent variable, and constants. The purpose of an experiment is to test how changing ONE THING affects something else.

Variables

Independent Variable: The thing that

I change Dependent variable: The thing that is measured

Remember Variables are always nouns!!! Variables NEVER have numbers in them!!!

Good experiments…

ONLY CHANGE ONE THING!!! Constant: things that we keep the same in the experiment

You must keep everything but the IV constant, or your data may not be valid!

Example

Let’s say we want to design an experiment to determine what causes GSP to win fights.

GSP wins fights

Determining variables from hypotheses “If Jay-Z stops cussing, he will sell fewer CDs because students like cussing.”

What is the IV? “What am I changing?”

What is the DV? “What am I measuring?”

What are the constants? “What stays the same?”

WARNING!!!!Almost everyone gets this wrong.

“If Jay-Z stops cussing, he will sell fewer CDs because students like cussing.” The IV is NOT “if Jay-Z stops cussing”

The DV is NOT “he will sell fewer CDs”

The control is NOT “students like cussing”

Remember Variables are always nouns!!! Variables NEVER have numbers in them!!!

How many CDs Jay-Z sells

Practice

You want to know if older microwaves heat food more slowly than new ones. So, you get a bunch of microwaves, write down their ages, and time how long it takes them to boil water.

IV =

DV =

Microwave Age

time to boil water

Practice

You want to know which season has the most love bugs. Every night, you record how many love bugs you find outside.

IV =

DV =

Season/month

Amount of love bugs

Practice

Students of different ages were given the same puzzle to assemble. The puzzle assembly time was measured.

IV =

DV =

Age

Puzzle Assembly Time

If there are more students, then

there will be more school buses.

IV =

DV =

Amount of students

Number of school buses

If the cost of beignets increases, then fewer will be sold.

What depends on what?

IV =

DV =

Cost of Beignets

Amount of Beignets sold

IV = Number of free agents

DV = number of games won

If the Saints sign more free agents, then they will win more games.

Conclusion

Key Point #1: A proper experiment always has an independent variable, dependent variable, and constants. Independent Variable: The thing that I change

Dependent variable: The thing that is measured

Constant: things that we keep the same in the experiment

Egg Lab!

An egg is ONE cell! Underneath the shell is a semi-permeable membrane… a cell membrane!

If we put this egg into a hypertonic/hypotonic solution, osmosis will occur.

Question

Will an unshelled egg increase or decrease in size after being placed overnight in a hypertonic (corn syrup) or hypotonic (water) solution?

Egg lab!

Read the procedures for the egg lab Fill out the hypothesis, IV, DV, and constants at the top of your egg lab worksheet Remember…

Good hypotheses are testable and educated IV is what I change DV is what I measure (it depends on the IV) Constants do not change

Once you have done all of this, check in with me. If you did a good job, I will let you begin the lab.

Exit Question

Mr. LY wants to see if boys are faster than girls at solving biology questions. He records how long it takes 10 boys and 10 girls to correctly solve the same homework problems.

What is the independent variable? What is the dependent variable? What is at least one constant?

After you get your computer running… Go to this website: http://school.discoveryeducation.com/sciencefaircentral/

On the brown tabs on the lower left, click virtual lab. Then, hit get started.

Click How Does Your Garden Grow Virtual Lab (Flash)