Docsity
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Science Experiments: Identifying Variables and Hypotheses, Study notes of Biology

Foundation University (FU)Biology

Instructions and examples for identifying independent and dependent variables in science experiments, creating hypotheses, and making and interpreting graphs. It includes helpful videos and practice problems. Students will learn how to set up experiments with control and experimental groups, and understand the importance of line graphs in science.

Typology: Study notes

2021/2022

Uploaded on 08/01/2022

hal_s95
hal_s95 🇵🇭

4.4

(655)

10K documents

1 / 12

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Name: ___________________________________________________________ Honors Biology
Welcome to Honors Biology!
In order to start the new school year off on the right foot, complete these practice problems. There are
readings and helpful videos to watch if you need them. Identifying variables, creating hypotheses and
making and interpreting graphs are skills needed throughout all of your high school science career.
Starting your freshman year off understanding how to accomplish these skills with mastery is key to being
successful. Please bring this finished packet with you in the fall, either electronic or paper copy.
We look forward to meeting you and a year full of experimenting together!
- Biology Honors Teachers
Identifying Variables & Hypothesis Review
HELPFUL VIDEOS
“Independent and Dependent Variables” - https://youtu.be/-mVHzIDN0A8
“ What are Independent, Dependent and Controlled Variables” - https://youtu.be/iaewZmc4TYQ
“Independent and Dependent Variables Made Easy” - https://youtu.be/_VdOB4JJE_8
“Writing a Hypothesis” - https://youtu.be/2sb6gw688Co
“What is a Hypothesis?” - https://youtu.be/id1OrxsIhQ0
HOW TO IDENTIFY VARIABLES
Independent Variable- One thing that the experimenter changes on purpose
Dependent Variable- Something that changes as a result of the independent variable (often what is measured)
Constant/Control Variable – Something kept the same on purpose
EXPERIMENT SET-UP
Experimental Group- is a test sample or the group that receives an experimental procedure. This group is exposed to
changes in the independent variable being tested. The values of the independent variable and the impact on the dependent
variable are recorded. An experiment may include multiple experimental groups at one time.
Control Group- is a group separated from the rest of the experiment such that the independent variable being tested
cannot influence the results. This isolates the independent variable's effects on the experiment and can help rule out
alternative explanations of the experimental results.
HOW TO WRITE A GOOD HYPOTHESIS USING “IF… THEN… BECAUSE…”
An “If… then…because” statement in a hypothesis tells the readers what you believe will happen in an investigation when
something is changed, so you can see the effect of the change.
IF…tells the readers what will be changed. This is the manipulated (independent) variable in the
investigation.
THEN… tells the reader what will happen because of the change (manipulated variable) described in the If…
statement. This is the responding (dependent) variable in the investigation.
BECAUSE… tells the reader how you know this will occur. It should be based on something you have
experienced, or perhaps something you infer.
Examples:
If 7th graders and 8th graders complete the same math problems, then the 8th graders will have more
answers correct, because they have studied math for one year longer than the 7th graders.
If some students eat breakfast before school and others do not, then the ones who do eat breakfast will
have better grades in their morning classes, because their brains have more energy to think.
pf3
pf4
pf5
pf8
pf9
pfa

Partial preview of the text

Download Science Experiments: Identifying Variables and Hypotheses and more Study notes Biology in PDF only on Docsity!

Name: ___________________________________________________________ Honors Biology

Welcome to Honors Biology!

In order to start the new school year off on the right foot, complete these practice problems. There are

readings and helpful videos to watch if you need them. Identifying variables, creating hypotheses and

making and interpreting graphs are skills needed throughout all of your high school science career.

Starting your freshman year off understanding how to accomplish these skills with mastery is key to being

successful. Please bring this finished packet with you in the fall, either electronic or paper copy.

We look forward to meeting you and a year full of experimenting together!

  • Biology Honors Teachers Identifying Variables & Hypothesis Review

HELPFUL VIDEOS

“Independent and Dependent Variables” - https://youtu.be/-mVHzIDN0A

“ What are Independent, Dependent and Controlled Variables” - https://youtu.be/iaewZmc4TYQ

“Independent and Dependent Variables Made Easy” - https://youtu.be/VdOB4JJE

“Writing a Hypothesis” - https://youtu.be/2sb6gw688Co

“What is a Hypothesis?” - https://youtu.be/id1OrxsIhQ

HOW TO IDENTIFY VARIABLES

Independent Variable- One thing that the experimenter changes on purpose Dependent Variable- Something that changes as a result of the independent variable (often what is measured) Constant/Control Variable – Something kept the same on purpose

EXPERIMENT SET-UP

Experimental Group- is a test sample or the group that receives an experimental procedure. This group is exposed to changes in the independent variable being tested. The values of the independent variable and the impact on the dependent variable are recorded. An experiment may include multiple experimental groups at one time. Control Group- is a group separated from the rest of the experiment such that the independent variable being tested cannot influence the results. This isolates the independent variable's effects on the experiment and can help rule out alternative explanations of the experimental results.

HOW TO WRITE A GOOD HYPOTHESIS USING “IF… THEN… BECAUSE…”

An “If… then…because” statement in a hypothesis tells the readers what you believe will happen in an investigation when something is changed, so you can see the effect of the change.  IF …tells the readers what will be changed. This is the manipulated (independent) variable in the investigation.  THEN … tells the reader what will happen because of the change (manipulated variable) described in the If… statement. This is the responding (dependent) variable in the investigation.  BECAUSE … tells the reader how you know this will occur. It should be based on something you have experienced, or perhaps something you infer. Examples:  If 7 th^ graders and 8th^ graders complete the same math problems, then the 8th^ graders will have more answers correct, because they have studied math for one year longer than the 7th^ graders.  If some students eat breakfast before school and others do not, then the ones who do eat breakfast will have better grades in their morning classes, because their brains have more energy to think.

Practice Problems #1- 6

DIRECTIONS : For each testable question (1 thru 6), UNDERLINE the independent variable, circle the dependent

variable, and list 3 constant/control variables. Then write a hypothesis in correct form.

1) How does the distance from an eye chart affect the number of letters that are recognized on a line? Constant/Control Variables: optometrist’s office , not wearing contact lenses or glasses, both eyes open. Hypothesis: If a person getting their eye exam stands closer to the eye chart, such as 10 feet, then they will recognize more letters because the eye exam was created for a person to stand 20 feet away 2) How does the amount of light affect the growth of a plant? Constant/Control Variables: _________________________________________________ Hypothesis: If_____________________________________________________________________ then __________________________________________________________________ because _______________________________________________________________ 3) How does the amount of oxygen in the water affect the oyster population? Constant/Control Variables: _________________________________________________ Hypothesis: If_____________________________________________________________________ then __________________________________________________________________ because _______________________________________________________________ 4) How will the amount of fertilizer used on a field affect the number of earthworms found there? Constant/Control Variables: _________________________________________________ Hypothesis: If_____________________________________________________________________ then __________________________________________________________________ because _______________________________________________________________ 5) How does the length of a string affect the number of times a pendulum will swing back and forth in 10 seconds? Constant/Control Variables: _________________________________________________ Hypothesis: If_____________________________________________________________________ then __________________________________________________________________ because _______________________________________________________________ 6) How does the size of a bicycle tire affect the distance it will travel when it is pedaled in a given number of times? Constant/Control Variables: _________________________________________________ Hypothesis: If_____________________________________________________________________ then __________________________________________________________________ because _______________________________________________________________

Practice Problems # 10 – 13

DIRECTIONS : For each scenario (10 thru 13) write a hypothesis.

10) The cooler the temperature in a lake, the more oxygen the water holds. Daniel notices that he catches more fish in a lake that is cooler than 55 degrees. He wants to conduct a study so he can catch the most fish possible this year. He’s having trouble writing a hypothesis. Please help him. Hypothesis: If the temperature of the lake is cooler than 55 degrees (independent variable) Then the amount of fish available to catch is greater (dependent variable) Because cold water can hold more oxygen, thus providing the fish more oxygen which leads greater population numbers. 11) Kasey lives in Moab, Utah. She likes to mountain bike for miles and miles until she can’t bike anymore. She thinks that she can bike further when she drinks more than a liter of water before her bike ride. Please assist her in developing a hypothesis, so she can make the best of her future bike rides. Hypothesis: If ____________________________________________________________ (independent variable) Then __________________________________________________________ (dependent variable) Because ________________________________________________________. 12) Jimmy likes to work with his friend Joe on 7th^ grade science class labs. However, he notices that he tends to get lower grades when he does work with Joe, because he and Joe like to talk about basketball and not science. He’s decided to investigate if his science lab grades are higher when he works with Joe or if they’re higher when he works with someone else. He has set goals to become a better student, so could you please help him write a hypothesis for his study? Hypothesis: If ____________________________________________________________ (independent variable) Then __________________________________________________________ (dependent variable) Because ________________________________________________________. 13) Mr. Montanari has noticed that there is a wide range of grades that students get on tests, even though they are all in the same class. He wonders whether students, who study for 20 minutes per night, every night, get higher scores on tests or not. Mr. Montanari wants as many kids to be successful as possible. Please help him write a hypothesis about this problem. Hypothesis: If ____________________________________________________________ (independent variable) Then __________________________________________________________ (dependent variable) Because ________________________________________________________.

Graphing Review

INTRODUCTION

Line graphs compare two variables. Each variable is plotted along an axis. A line graph has a vertical axis and a horizontal axis. For example, if you wanted to graph the height of a ball after you have thrown it, you would put time along the horizontal, or x-axis, and height along the vertical, or y-axis.

HELPFUL VIDEOS

“A Beginners Guide to Graphing” - https://youtu.be/9BkbYeTC6Mo “Graphing Data by Hand” - https://youtu.be/GUYRMdcEs

LINE GRAPHS ARE IMPORTANT TO SCIENCE FOR SEVERAL REASONS, SUCH AS:

  • showing specific values of data. If one variable is known, the other can be determined.
  • showing trends and relationships in data clearly. They visibly depict how one variable is affected by the other as it increases or decreases.
  • allowing the viewer to make predictions within recorded data, called interpolation , and to make predictions about data not yet recorded, called extrapolation.

INTERPOLATION vs. EXTRAPOLATION

Determine which of the examples below is interpolation and which is extrapolation. Explain why.

  1. The value of Sarah’s car in 2004 was $17,500. ______________________________________________________
  2. The value of Sarah’s car in 2008 was $1,900. _______________________________________________________

HOW TO CONSTRUCT A LINE GRAPH:

  1. Identify the Variables & Label the Axes a. Independent Variable – factor that is varied in an experiment and specifically controlled by the experimenter i. Label along the x-axis (horizontal) – include units ii. Typically found on the left side of a data table b. Dependent Variable – factor that is measured in an experiment and will change as a result of the independent variable i. Label along the y-axis (vertical) – include units ii. Typically found on the right side of a data table Independent vs. Dependent Variable Practice A student wanted to observe how changing the temperature of the aquarium water would affect the breathing rate of his goldfish. o What is the independent variable? ___________________________________________ o What is the dependent variable? ____________________________________________ A student wanted to determine how tall corn would grow if different types of fertilizer were used. o What is the independent variable? ___________________________________________ o What is the dependent variable? ____________________________________________

Graphing Practice Practice Problem # Background: The thickness of the annual rings indicates what type of environmental situation was occurring the time of the tree’s development. A thin ring usually indicates a rough period of development such as lack of water, forest fires, or insect infestation. On the other hand, a thick ring means a prosperous period of development. Use the information from the data table below to create a proper scientific graph and to answer the corresponding questions. Age of Trees (in years) Average Thickness of Annual Rings in Forest A (millimeters) Average Thickness of Annual Rings in Forest B (millimeters) 10 20 24 20 24 28 30 30 35 35 34 38 50 41 45 60 46 51

  1. What is the dependent variable? ________________________________________________________________
  2. What is the independent variable? _______________________________________________________________
  3. What was the average thickness of annual rings for 40 year old trees in Forest A? _________________________
  4. What is it called when you make predictions within given data, such as made in question #3? ________________
  5. What was the mean thickness of annual rings for all trees found in Forest B? _____________________________
  6. Based on the data shown, what can be concluded about the comparative health of Forest A & B? ____________
  7. What type of relationship (constant, direct, or indirect) exists between the age of trees and the average thickness of the tree’s rings? Explain. ____________________________________________________________

Practice Problem # Background: Natalie sets out to run 15 kilometers. Every 30 minutes she checked her pedometer to determine how far she had run. Use the data below to create a proper scientific graph and to answer the corresponding questions. Time (minutes) Total Distance (km) 0 0 30 6. 60 10. 90 12 120 13. 150 15

  1. What is the dependent variable? ________________________________________________________________
  2. What is the independent variable? _______________________________________________________________
  3. How many kilometers had Natalie run after 40 minutes? _____________________________________________
  4. What was Natalie’s average speed (in kilometers per hour) over the course of her run? ____________________