GraceSnyder& UnitPlan&&...

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Grace Snyder Unit Plan Fall 2014 Topic: Cells

Grade: 10th Grade Biology

Length: 21 days

Essential Question: Why are cells considered to be the basic unit of life?

Standards:

• Nebraska State Science Standards

o Content: SC12.3.1 Students will investigate and describe the chemical basis of the

growth, development, and maintenance of cells

• SC12.3.1.a Identify the complex molecules (carbohydrates, lipids, proteins, nucleic

acids) that make up living organisms

§ SC12.3.1.b Identify the form and function of sub-‐cellular structures that regulate

cellular activities

o Inquiry

§ SC12.1.1.a Formulate a testable hypothesis supported by prior knowledge to guide

an investigation

§ SC12.1.1.d Select and use lab equipment and technology appropriately and

accurately

§ SC12.1.1.f Represent and review collected data in a systematic, accurate, and

objective manner

§ SC12.1.1.g Analyze and interpret data, synthesize ideas, formulate and evaluate

models, and clarify concepts and explanations

• Next Generation Science Standards

o HS-‐LS1-‐6. Construct and revise an explanation based on evidence for how carbon,

hydrogen, and oxygen from sugar molecules may combine with other elements to form

amino acids and/or other large carbon-‐based molecules.

o HS-‐LS1-‐3. Plan and conduct an investigation to provide evidence that feedback

mechanisms maintain homeostasis.

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Day

Inquiry Phase (4Es) and Learning

Theory/Principle

Learning Activity

Talking or Writing Structure/ Instructional Strategy

Academic Language Support Strategy

Assessment activity (5th E Evaluate).

1

Engage

LP1: Accessing

prior knowledge

Students try to come up with complex molecules in table groups

Share list on white boards with the whole class

Diagnostic: See students’ prior knowledge of complex molecules

Explore

LP2: Factual and conceptual knowledge development

Food Activity: look at food labels to examine the amount of lipids, carbohydrates, and protein in common foods

Make a table on class board. Create a think pare share, each table group will examine different foods and then share on table

Post the three complex molecules on the board Class Table

2

Explain I


Food Activity continued

Students use sugar and butter to represent (on a scale) the amount in food Present to the class their finding.

Explain II


Direct instruction on the basic chemical structure and general properties of carbohydrates, lipids, proteins, and nucleic acid

Draw and label structures

Formative: Exit Ticket

3

Elaborate

LP3: Self-‐Monitoring and Metacognition

Who Took Jerell’s iPod? Lab part 1 (Appendix p. 8-‐11)

Students follow the lab handout

Summative: Lab worksheet

4

Elaborate


Who Took Jerell’s Ipod? Lab part 2 (Appendix p. 12-‐15)

Students must design their own plan solve the mystery.

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5

Engage

LP1: Accessing prior knowledge

Competition of which group can remember: • 7 Characteristics of Life

• Organization of Life

• Cell Theory

In table groups work to come up with the 7 characteristics of life, the organization of life, and the 4 parts of the cell theory

Create a class table

Diagnostic: See students’ prior knowledge of the 7 characteristics of life, the organization of life, and the 4 parts of the cell theory

Explore


Student debate Students will investigate through a debate the validity of the 3 principles, (e.g. 7 vs. 8 characteristics)

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Explain I


Student government agreement

As a class, students will agree upon these 3 principles. The class will divide up into three groups and create a poster to represent each principle, including pictures.

Post: Characteristics of Life, Organization of Life, and Cell Theory

Explain II Direct instruction on decided principles

Engage Video, Why are cells small? (http://www.youtube.com/watch?v=wuXSEOKNxN8)

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Explore


Cell size activity, surface area to volume ratio (Appendix p. 16-‐17)

Explain I

LP1: Accessing prior knowledge

KWL: Cells and organelles

Form KWL alone, then combine in table groups and write on small white board. Share white boards with class

Class KWL on the board

Diagnostic: See students’ prior knowledge of cells and their organelles

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Explain II


Animal cell framework: draw in organelles and write about their function (Appendix p. 18)

Start lecture based on what students said in their KWL about their knowledge of the structure and function of the cell membrane, cytoplasm, nucleus, mitochondria, ribosomes, endoplasmic reticulum, golgi apparatus, and lysosome

Draw organelles with class on board. Post organelle vocabulary Question Wall: leave any questions after class

Formative: See students’ misconceptions from the question wall

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10

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Explore


Inside a cell, interactive 3D cell (http://learn.genetics.utah.edu/content/cells/insideacell/)

Explain I


Graphic Organizer Students will create a graphic organizer in groups of 2-‐3 to connect how the organelles work together.

Formative: Check students knowledge of organelle relationships

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Explain II


Plant cell framework: draw in organelles and write about their function (Appendix p. 19)

Question Wall: leave questions after class

Lecture over cell wall, chloroplasts, and vacuole structure and function

13 Elaborate


Candy Cell (Appendix p. 20-‐21)

Student work day

Summative: Candy Cell 14

15 Student’s present their cell to the class

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16

Engage


Find similarities and differences in pictures

Show students pictures of eukaryote and prokaryote cells with no descriptions

Explore


Prokaryote and eukaryote worksheet (Appendix p. 22-‐23)

Explain I


Venn Diagram Prokaryote vs. Eukaryote class discussion creating Venn diagrams.

Class Venn diagram

Summative: Prokaryote and eukaryote worksheet

Explain II

Direct instruction on students’ Venn diagrams

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Elaborate LP2: Factual and conceptual knowledge development

Cheek cell Lab (Appendix p. 24-‐25)

Summative: Lab worksheet

Engage

LP1: Accessing prior knowledge Gummy Bear Lab

(Appendix p. 26-‐27)

Students will make prediction and do procedures up to #4, d.

18

Explore


Do lab until #8, then students create their own experiment

Summative: Lab write up

19

Explain I


Sticky Note Graph

Students in groups will come up with their own definitions or examples of hypertonic, hypotonic, isotonic

Explain II


Sticky Note Graph

Fill in any gaps of misconceptions or lack of knowledge from the sticky note graph

Group sticky note graph

Formative: See students’ prior knowledge of hypertonic, hypotonic, isotonic

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20


Student Review Day

Have conferences with students to let them know where they need to focus their study time.

21 LP3: Self-‐Monitoring and Metacognition

Test Day Summative: Test

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Assessment of Student Learning The unit begins and ends with assessment. When introducing a new concept, the unit is

planned out so that a formative assessment of students’ prior knowledge is implemented. These

include activities such as: KWLs, small white board discussions, question wall, graphic organizer,

Venn diagram, and sticky note graph. This is done so that I know what concepts to focus on and

any misconceptions can be addressed and corrected right away. Throughout the unit, formative

assessments will also be done daily to determine how well the students responded to the learning

activity. If they struggled with anything, I will plan to spend more time the following days

addressing that.

The unit ends with a major summative assessment, a unit test. Prior to this there are

several small summative assessments. These include all labs and worksheets. It is important to

give students chances to show their understanding and get points for the work that they do.

Because some students struggle at test taking, the candy cell project and presentation will be

worth a high amount of points also. This gives students a constructive and alternative way to

show their knowledge besides the test.

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Appendix Source: http://serendip.brynmawr.edu/sci_edu/waldron/

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Who took Jerell’s iPod? -- An organic compound mystery1 Jerell is a 10th grade student who works at McDonald’s on the weekends. While on break, Jerell was studying for his biology test and listening to his new iPod. There were four other workers taking a break at the same time, each having something different for lunch. Jerell‘s girlfriend stopped by near the end of his break, and he rushed out to see her and forgot his iPod and biology book in the break room. When he realized, he hurried back and found only his biology book and some spilled food. His iPod was gone! At first Jerell freaked out, but he calmed down when he realized he could use his knowledge of organic compounds to figure out which of his coworkers left the spilled food on his biology book while taking his iPod. What are organic compounds? Almost all of the food we eat comes from plants and animals. Plants and animals contain mainly water and organic compounds, which are molecules made by living organisms such as plants or animals. 1. The table below lists the most common types of organic compounds found in living organisms. For each type of organic compound, give one or two examples and describe one characteristic, e.g. whether it is greasy, whether it contains genetic material, whether there is lots of this type of organic compound in meat or lots in pretzels and potatoes.

Type of Organic Compound

Examples Characteristic of This Type of Organic Compound

Carbohydrates

Lipids

Nucleic acids

Proteins

2. Today you will be testing the substances listed in the following table. Predict whether each substance is an organic compound and if so, what type.

Substance Do you think this substance is a carbohydrate, lipid, protein, or none of these?

Vegetable oil Glucose Starch from corn or potatoes Powdered egg whites Water

1 By Drs. Jennifer Doherty, Ingrid Waldron and Lori Spindler, Department of Biology, University of Pennsylvania, copyright 2012; adapted from “Identity of Organic Compounds” from Biology Laboratory Manual A from Prentice-Hall; also inspired by “Crime Scene Activity” by Kathy Paris, Bethel High School http://www.accessexcellence.org/AE/ATG/data/released/0535-KathyParis/index.php .Teachers are encouraged to copy this Student Handout for classroom use. A Word file, which can be used to prepare a modified version if desired, and Teacher Preparation Notes are available at http://serendip.brynmawr.edu/sci_edu/waldron/.

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What are indicators? An indicator is a substance that changes color in the presence of a particular type of molecule. Today you will learn how to use several indicators to test for the presence of carbohydrates and proteins. You will also use a different type of test for lipids. In your next laboratory period, you will use these tests to analyze the evidence left at the scene of the crime and find out who spilled the food on Jerell’s textbook. Testing for lipids 1. If a food that contains lipids is put on brown paper, it will leave a spot that lets light through. To

test for lipids, divide a piece of a brown paper bag into 5 sections. Label the sections "vegetable oil", "glucose", "starch", "powdered egg whites", and “water”.

2. In each section, rub a small amount of the substance onto the brown paper. With a paper towel, rub off any excess that may stick to the paper.

3. Set the paper aside until the spots appear dry—about 10 to 15 minutes. While you are waiting,

answer questions 4 and 5 and then continue with the tests on page 3. 4. Which substance or substances do you expect to test positive for lipids? 5. What is the purpose of testing water for lipids?

6. Why should you test all of the substances for lipids even though you believe that some of them do not contain lipids?

7. Continue on with the tests on page 3. After all the sections of the brown paper are dry, hold the paper up to a bright light or window. You will notice that at least one sample has left a spot on the brown paper that lets light through. This type of spot indicates the presence of lipids.

8. Complete the last column of the data table below. Put a plus for any samples that tested

positive for lipids and a minus for the samples that did not.

Sample Carbohydrate Tests Protein Test Lipid

Test Test strip

color Glucose present

Iodine test color

Starch present

Biuret test color

Protein present

Lipid present

Vegetable oil

Glucose

Starch from corn or potatoes

Powdered egg whites

Water

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Testing for Carbohydrates 1. You will be using chemicals as indicators. You must wear gloves to protect yourself.

2. You will use indicators to test for two common types of carbohydrates: glucose (a specific type

of sugar) and starch. Obtain 5 containers and use masking tape to make labels for each container. Label the containers "vegetable oil", "glucose", "starch", "egg whites", and “water”.

3. For each container, add a small amount of the substance indicated on the masking-tape label.

Next, add about 2 ml of water to each container. Stir the contents of each container to mix the substance with the water.

4. To test for glucose you will use a test strip with an indicator pad that changes color in the presence of glucose. Prepare a piece of paper with the name of each substance and a place to put the glucose test strip you have used to test that substance. Dip one test strip into each sample for 1-2 seconds. Remove the strip, put it in the appropriate spot on your labeled paper, and wait 3 minutes.

5. Which substance or substances do you expect to test positive for glucose?

6. After 3 minutes, look for a color change in each of the glucose test strips and record the color of

each glucose test strip in the data table on page 2. Put a plus next to those samples testing positive for glucose and a minus for those testing negative.

7. To test for starch you will use iodine as an indicator. In the presence of starch, iodine will

change color from yellow-brown to blue-black. Add 5 drops of iodine solution to each container. Stir the contents of each container.

CAUTION: Be careful when handling iodine; it can stain hands and clothing.

8. In the data table on page 2, record the color of the iodine solutions. Put a plus next to those samples testing positive for starch and a minus for those testing negative.

Testing for Proteins 1. Label five clean containers "vegetable oil", "glucose", "starch", "egg whites", and “water”. Add a

small amount of the substance indicated on the label to each container. Add about 2 ml of water to each container. Stir the contents of each container to mix the substance with the water.

2. To test for protein you will use Biuret reagent as an indicator. Biuret reagent turns from blue to purple in the presence of protein. Add 20 drops of biuret reagent to each container. Stir the contents of each container. CAUTION: Biuret reagent contains sodium hydroxide, a strong base. Be very careful not to splash or spill any. If you splash any reagent on yourself, wash it off immediately with water. Call your teacher for assistance.

3. Record the color of each Biuret solution in the data table on page 2. Put a plus next to those samples testing positive for protein and a minus for those testing negative.

4. Rinse all ten containers thoroughly.

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Questions 1. Compare your predictions in the table on page 1 with your test results in the table on page 2.

Were there any differences between your test results and your predictions for what type of organic compound each substance is? If yes, describe these differences.

If you found any differences between your predictions and your results, what do you think is the reason for these differences? You may want to check with your teacher, your textbook, or the nutrition information in the label on each food package to help you interpret your results.

2. Did your test for glucose indicate there was glucose in the starch sample?

Does that mean that there is no glucose in starch? (Hint: Check your textbook or other reliable source if you do not already know the chemical structure of starch.)

This result shows that the glucose indicator is quite specific. It reacts with glucose dissolved in water, but it does not react with glucose molecules that are combined into a large organic compound like starch.

3. Humans get the protein they need from foods, including beans and milk. A bean is a plant seed

which contains a tiny plant embryo, together with food to help the plant embryo grow. Cows and other mammals produce milk to provide the food their babies need to grow. Seeds and milk contain proteins, fats, sugars and/or starch. Explain how the fats, sugars and/or starch contained in seeds or milk are useful for the plant sprouting from the seed or the baby mammal. Explain how the protein contained in seeds or milk is useful for the plant sprouting from the seed or the baby mammal.

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Part II – Solving the Mystery Today you and your classmates will solve the mystery of who stole Jerell's iPod by figuring out which coworker's lunch had the same organic compounds as the evidence Jerell found at the crime scene. 1. Begin by predicting which types of compounds you expect to find in each type of food.

Food Do you expect this food to contain Glucose? Starch? Protein? Lipid?

Pretzel Butter Jelly Fat-free yogurt Beans

2. Your teacher will assign you a sample or samples to test. Use the procedures described on pages 2-3 to test the sample or samples for the four types of organic compounds. (The evidence that Jerell found has been separated into dry and liquid evidence in two separate bottles.) 3. Record your test results in the data table below. For each glucose test strip, record the specific matching color from the glucose test strip bottle or packet (needed for question 3 on page 8). 4. After you perform the tests, your teacher will collect your data to share with the rest of the class. Use the data from your classmates to complete the table below.

Food Carbohydrate Tests Protein Test Lipid

Test Test strip

color Glucose present

Iodine test color

Starch present

Biuret test color

Protein present

Lipid present

Pretzel (crumble into the container)

Butter

Jelly

Fat-free yogurt

Beans (mash into

a paste)

Dry part of Jerell’s

evidence

Liquid part of Jerell’s

evidence

5. Compare your predictions in the top table with the results in the bottom table. Were there any differences? If yes, describe these differences.

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6. If you found any differences between your predictions and your results, what do you think is the reason for these differences? You may want to check with your textbook, your teacher, or the nutrition information in the label on each food package to help you interpret your results. Who took Jerell’s iPod? 7. The table shows what each worker in the break room was eating while Jerell was studying. Use the information from the table on the bottom of page 5 to complete this table to show which types of organic compounds would be in each lunch and which types of organic compounds were found in the combined liquid + dry evidence.

Worker in break

room Lunch he or she was eating Glucose Starch Protein Lipid

Jose Bean burrito with cheese Ashley Fat-Free Yogurt Bruce Toast with butter and jelly Kiara Pretzel Thief Combined liquid + dry evidence

8. Complete the following table to summarize the evidence and your interpretation of the evidence.

Worker in break

room

Did he/she take

Jerell’s ipod?

How do you know? Describe the evidence that supports your conclusion.

Jose

Ashley

Bruce

Kiara

9. Who took Jerell’s iPod? Do you have any doubts about your conclusion? Explain.

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Review and Discussion Questions 1. To show your understanding of organic compounds, identify the type of organic compound shown in each diagram and complete the first three columns of the table. Many large organic compounds are made of multiple repeats of smaller building block compounds. Starch, proteins, and nucleic acids are examples of this type of organic compound. Circle a building block in the starch, protein, and nucleic acid figures, and write the name of the building block in the fourth column. Type of Organic

Compound Functions

Which test is used to detect this

compound or type of compound?

Name of building

block

Diagram of Structure of Organic Compound

Glucose

Not tested for

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2. Our bodies are made up of the same types of organic compounds as all other living organisms. Complete the following sentences by filling in each blank to indicate the function of each type of molecule in different parts of our body.

Glucose is carried by our blood to all the cells in our body. Our cells use the glucose for _______________. Lipids are found in fat cells in our bodies. The fat cells store lipid molecules to be used for ______________ if a person can not get enough food. Our bodies do not make starch, but we often eat plant foods which contain starch which we digest into _____________, the building block that is used to make starch. DNA is a nucleic acid that is found in every cell. DNA carries the ____________ information. Our muscles contain lots of protein. This protein enables the muscles to _____________.

3. In this activity you have recorded whether an indicator tested positive or negative for each type of organic compound. We have ignored the fact that different foods contain different amounts of the various types of organic compounds. For the five foods listed in the table on the bottom of page 5, list these foods in order from the food with the most glucose to the food with the least glucose. Some foods may test positive for glucose, but do not taste sweet. What is a possible explanation? Some foods may taste sweet, but have very little glucose. What is a possible explanation? 4. Sophisticated laboratory analysis of pretzels, fat-free yogurt, and beans indicate that all three of these foods contain at least a little bit of lipid and protein. Did you and your classmates get positive tests for lipids and proteins in all three of these foods? (Check the bottom table on page 5.) If any of your class’s tests for lipids and proteins in these foods were not positive, what reason or reasons could account for these negative findings?

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Source: https://www.nsa.gov/academia/_files/collected_learning/high_school/geometry/surface_area.pdf

Nets (Patterns) for Cubes

Activity 1 To explore the surface area and volume formulas for a cube, you are to cut out and tape the following two-dimensional versions of cubes into three-dimensional versions:

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Name:

Animal Cell

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Name: Plant Cell

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Candy Cell Procedure:

Divide up into groups of 2-3. Create a cell model of either a plant or animal cell in a plastic, clear, container.

Different types of candy will represent the organelles. Keep in mind the shape and purpose of each organelle

as you select your materials. Each of the following organelles must be represented in your model (depending

on your choice of plant or animal cell):

1. Nucleus

2. Mitochondria

3. Ribosomes

4. Golgi Apparatus

5. Endoplasmic Reticulum

6. Cytoskeleton components (ex. microtubules)

7. Chloroplasts

8. Cell wall/cell membrane

Day 1

After choosing a cell to model, draw a sketch. Identify each of the organelles in your model (as well as the

candy that represents it). Next, divide up who is bringing each item to class (remember to include the

container). Glue, tape, string, and scissors will be provided. After this is finished ask for approval of your

plan.

Day 2

Bring all the parts needed for your cell model. The class period will be spent assembling your cells.

Day 3

Groups will present their finished models to the class. Each group will be graded on having all the

organelles present, describing where each organelle is and what it is made of, telling the function of the

organelle, and having equal participation from group members.

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=char(32)

Building A Structure : Candy Cell

Teacher Name: Grace Snyder

Student Name: ________________________________________

CATEGORY 4 3 2 0-1Construction -Materials

Appropriatematerials wereselected andcreativelymodified in waysthat made themeven better.

Appropriatematerials wereselected andthere was anattempt atcreativemodification tomake them evenbetter.

Appropriatematerials wereselected.

Inappropriatematerials wereselected andcontributed to aproduct thatperformedpoorly.

Construction -Care Taken

Great care takenin constructionprocess so thatthe structure isneat, attractiveand follows plansaccurately.

Constuction wascareful andaccurate for themost part, but 1-2details couldhave been refinedfor a moreattractiveproduct.

Constructionaccuratelyfollowed theplans, but 3-4details couldhave been refinedfor a moreattractiveproduct.

Constructionappears carelessor haphazard.Many detailsneed refinementfor a strong orattractiveproduct.

Function Organellefunctions wereexplainedextraordinarilywell, allorganelles wereincluded

Organellefunctions wereexplained well,all organellesincluded

Organellefunctionsexplained well,but not allorganellesincluded

Organellefunction was wasminimallyexplained

Plan Plan is neat withclearmeasurementsand labeling forall components.

Plan is neat withclearmeasurementsand labeling formostcomponents.

Plan providesclearmeasurementsand labeling formostcomponents.

Plan does notshowmeasurementsclearly or isotherwiseinadequatelylabeled.

Presentation All materialswere explainedand presentedequally by groupmembers

All materialswere explainedbut grouppresentation wasnot equal

Few materialswere explained,presentationequal

Few materialsexplained andgrouppresentation wasnot equal

Date Created: Apr 21, 2014 02:23 pm (CDT)

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Name%____________________________________________________%Period%___________%Date%___________________%

Cell$Structure:$Prokaryotes$and$Eukaryotes$

What’s'the'Difference?'

Look%at%the%two%drawings%of%prokaryotes%and%eukaryotes;%discuss%with%your%partner%the%

similarities%and%differences%between%the%two%cells.%

$

$

$

$

$

$

$

$

$

$

$

$

List$the$five$parts$that$Prokaryotes$and$Eukaryotes$both$have:$

1.%___________________________%%

2.%___________________________%%

3.%___________________________%%

4.%___________________________%(with%just%Plant&Eukaryotes)&&

5.%___________________________%(with%just%Animal&Eukaryotes)&

Do%Prokaryotes%have%a%nucleus?%________%%

Which%is%more%complex,%Eukaryotes%or%Prokaryotes?%_______________________%%

Which%is%larger?%____________________%

Why'are'cells'named'that'way?'

From%Greek%words...%EU%means%__________________.%PRO%means%__________________.%KARY%means%

__________________.%Eukaryote%=%____________________;%Prokaryote%=%____________________.%%

All%cells%have%____________________,%in%eukaryotes%it%is%stored%in%the%____________________.%Prokaryotes%

don’t%have%a%nucleus,%and%it%floats%around%in%the%cytoplasm%in%an%area%called%a%____________________.%

Only%eukaryotes%have%____________________.%

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Test$Yourself:$Which%type%has....?%Place%a%check%or%X%in%the%table%below%if%the%statement%is%true%for%each%cell%type.%Statement$ Prokaryotic$ Eukaryotic$

1.%Have%a%nucleus%% $ $

2.%Have%membraneWbound%organelles% $ $

3.%Contain%genetic%material%(DNA)% $ $

4.%Can%be%single%or%multiWcelled% $ $

5.%Can%only%be%singleWcelled% $ $

6.%Have%a%plasma%membrane%and%cytoplasm%% $ $

$

Microscope'Review:'

1. What%are%the%two%common%types%of%microscopes%and%what%are%the%differences%between%them?$%%%$

2. Rule%of%Care:%Fill%in%the%blanks$Always%carry%with%____________________%Always%begin%on%_______________________%power%with%stage%all%the%way________________%%Always%focus%____________________________%When%turning%objectives%to%high%power______________________________________%Always%put%slides____________________%Always%clean%lenses%with_____________________________%Always%use%a%_________________________on%high%power%Put________________%on,%with%microscope%on%________________________power%with%stage_____________%to%put%away%%

3. Magnification:%$Eye%Piece:%% % Scanning:% % Low:%% % % High%% % % %

Total:% % % Total:% % % Total:%%

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Source: http://www.lessonplansinc.com/science.php?/biology/lessonplans/C83/

Name ______________________________

The Human Cheek Cell 1. List the 3 parts of the Cell Theory 2. Describe or define each of the following --cell membrane --cytoplasm --nucleus --organelle 3. Sketch the cell at low and high power. Label the nucleus, cytoplasm, and cell membrane. Draw your cells to scale. Low Power High Power 4. Why is methylene blue necessary? 5. The light microscope used in the lab is not powerful enough to view other organelles in the cheek cell. What parts of the cell were visible.

Procedure: v Put a drop of methylene blue on a slide. Caution:

methylene blue will stain clothes and skin. v Gently scrape the inside of your cheek with the

flat side of a toothpick. Scrape lightly. v Stir the end of the toothpick in the stain and

throw the toothpick away. v Place a coverslip onto the slide v Use the SCANNING objective to focus. You

probably will not see the cells at this power. v Switch to low power. Cells should be visible, but

they will be small and look like nearly clear purplish blobs. If you are looking at something very dark purple, it is probably not a cell

v 7. Once you think you have located a cell, switch to high power and refocus. (Remember, do NOT use the coarse adjustment knob at this point)

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6. List 2 organelles that were NOT visible but should have been in the cheek cell. 7. Is the cheek cell a eukaryote or prokaryote? How do you know? 8. Keeping in mind that the mouth is the first site of chemical digestion in a human. Your saliva starts the process of breaking down the food you eat. Keeping this in mind, what organelle do you think would be numerous inside the cells of your mouth?

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Source: http://serc.carleton.edu/sp/mnstep/activities/26990.html

Observing Osmosis

In this activity, you will investigate the affect of water on objects, using gummy bears. Question: What effect, if any, does soaking Gummy Bear candies in water have on the size of the candy? 1. Prediction: Write your prediction in your science journal based on the knowledge you already have and what you know what gummy bears are made out of. 2. Before you continue, read the activity and design a data-‐collection table on your group’s white board. 3. After the class discussion, write down a data collection table in your journal to fill in as you continue. 4. Procedure:

a. Label your beaker with your names. b. Fill in your data table with the height and weight of your candy bear. c. Record descriptive observations about the candy bear. d. Put your candy bear in a container with water covering the bear and set the container aside

until the next day. e. After the candy bear has been in the water overnight, gently take it out of the water and pat

it dry. Be very careful because the candy is now extremely breakable. f. Fill in your data table with the height, width, mass, and descriptive observations.

5. Calculate the following percent changes in the size of the candy and record in your notebook: % change in height % change in width % change in mass **Percent change = (After soaking measurement -‐ Before soaking measurement/ Before soaking measurement) x 100 **Make sure to label your answer with correct units 6. Graph the percent changes on a bar graph. You may use graph paper and cut and paste the graph into your science notebook. Remember to title and label both axes on your graph. 7. Look over the following information and use the vocabulary words to answer the questions below.

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Molecules are in constant motion and tend to move from areas of higher concentrations to lesser concentrations. Diffusion is defined as the movement of molecules from an area of high concentration to an area of low concentration. The diffusion of water molecules through a selectively permeable membrane is known as osmosis. Movement through membranes is called transport. Diffusion and osmosis are passive forms of transport; this means that they do not need energy to move from areas of high concentration to areas of low concentration.

a. What happened to the candy after soaking in water overnight?

b. Why did you get these results?

c. What do you think would happen to the candy if you let it soak in a different solution? Explain your answer. Set up the experiment, including taking the initial measurements and adding another data table in your notebook.

d. Write a scientific explanation that states the results of your investigation. Include a claim,

evidence, and reasoning.

e. List any questions you still have. 8. After the gummy bear has spent the night in your solution water, fill out your data table. 9. Write your findings in your lab notebook. Why do you think it reacted the way it did? What other solutions might be interesting to try putting a gummy bear in?

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