Solving Genetic Puzzles

Designed By: Canisha Fletcher  School: Hand Middle 

Grade Level: 7th      Subject: Science (with Math Integration) 

State Standard Curriculum Objectives: 1) Construct and use Punnett Squares to explain how single genetic traits are combined and passed to offsprings 2) Calculate the probability of simple phenotypes and genotypes 

Restatement: The students will be able explain the combination of genetic traits using a Punnett Square and determine the probability of genotypes and phenotypes 

Overview: The students will work in groups to construct and analyze various Genetic Puzzles using Punnett Squares. The groups will use manipulatives for this lesson. 

Focus Questions: 1) What is a genotype and a phenotype? 2) How useful are Punnett Squares when explaining the combination of genetic traits? 

Time Frame: 2 to 3 fifty - minute class periods 

Materials / Resources: 
Transparency of "Pheno" and "Geno" and "Type" - See attachment 

Punnett Square Mat- transparency for teacher and 1 laminated copy per group 

Science Notebook 

Dry Erase Markers (2 different colors per group) 

Paper Towel 

1" x 1" labeled paper markers- "Y" -yellow; "y"- green; "T" - blue; "t" - red (make an overhead set for teacher use) 

Solving Genetic Puzzles Cooperative Sheet- one per group 

Solving Genetic Puzzles Assessment Sheet - one per group 

Solving Genetic Puzzles Assessment Rubric - one per group 

Culminating Assessment: 
Solving Genetic Puzzle Assessment Rubric- The students will receive the rubric before the assessment activity. The groups will be assessed on correct completion of the Punnett Squares and clear, detailed answers for each genetic puzzle. 

Each group member will sign the rubric stating that he/she agrees with the responses and actively participated in the group. See Attachment 

Instructional Activities: 
Activity One - Exploring the Concept Vocabulary- 8 to10 minutes 
1) Place the students in groups of three. Assign the following roles: Material/Drawer; Reader; Recorder

2) Inform the students that they will need their Science Notebooks for the following lesson. 

3) This activity will introduce the concept vocabulary: Phenotype and Genotype 

4) Place the Greek Root "Pheno" on the overhead. See Attachment 

5) Ask the students to orally state the meaning. Some of them may/may not know it. After several (2 to 3) attempts, inform the students of the meaning- To show / To be visible. Instruct the students to write it in their notebook. Remove the transparency. 

6) Repeat the same process with the Greek Root "Geno." Meaning- Of the same kind or race 

7) Repeat the same process with the root "Type." Meaning - A mark or Sign 

8) Have the groups work for 2 to 3 minutes to create a definition for Phenotype and Genotype. Select several (3 to 4) groups to share. Write the definitions on the overhead. If a group creates a similar definition to the dictionary, use it. If not assist the class in revising their definitions until matches the dictionary definition. (Phenotype: the visible appearance of inherited traits; Genotype: the actual combination of genes) 

9) The students should record the definitions in their science notebook.

Activity Two- Solving Genetic Puzzles - Teacher Directed 
1) The students should have prior knowledge of the following concepts: dominate traits, recessive traits; hybrid crossing, which were taught in previously in the Genetics unit. Also, inform that students that everyone is curious about why we look the way we do. This lesson will provide one simple explanation. 

2) The materials person should gather the following materials: Punnett Square Mat, Markers, Dry Erase Markers, copies of the Solving Genetic Puzzle Cooperative Group Sheet (turn it face down during this activity) and a sheet of Paper Towel. The teacher should have all materials needed. 

3) The teacher will review Mendel's Pea Plant experiment (yellow - seeded hybrid) with the students by using a Punnett Square. Allow the students to record the definition of Punnett Square in their notebook. (Punnett Square: a chart that shows the possible combinations of genes that are passed from parent to offspring.) 

4) Position the overhead transparency mat and instruct the groups to use the laminated mat. Place the yellow and green markers on the mat. See below. Use the concept vocabulary while teaching this lesson.

5) Have the recorder physically move the markers so that one marker from the horizontal and vertical line is in each square. While the recorders are working, do the same and discuss the fact that when a hybrid produces sex cells, each sex cell will carry either a gene for yellow seeds (Y) or a gene for green seeds (y), but not both. (Relate the square to a coordinate grid.) 

6) Ask the groups to observe the combinations. Ask them how many offsprings will have the phenotype of yellow and how many will have the phenotype of green? Label the horizontal line - male / dominate genotype; vertical line - female / recessive genotype. Also inform the students that that large square (100%) is divided into four equal parts (25%).

7) Ask the groups to answer the previous question using probability terminology. 

Examples: 
Yellow = 75% 
Green = 25% 
3 yellow for every 1 green 

8) Have each student copy the completed Punnett Square in his/her notebook.

Activity Three- Solving Genetic Puzzles in Cooperative Groups

1) The groups will use the red and blue markers and the Solving Genetic Puzzles Cooperative Group Sheet. See Attachment The groups will work together to complete the sheet. 

2) "A" on the sheet is teacher guided. Monitor the progress of groups for B - D. Place a time limit (20 - 25 minutes.

Activity Four- Solving Genetic Puzzles Assessment

1) Materials needed: Assessment sheet and pencil 

2) The groups will work together to complete the sheet and each member must sign the assessment sheet. Set a time limit (20 to 25 minutes). See Attachment.

Attachment One: Concept Vocabulary Make a transparency and cut out each word.

Attachment Two: Cooperative Sheet

Solving Genetic Puzzles - Cooperative Groups 

Directions: The readers will read each statement to the group. Use the designated manipulatives, when needed. The Materials and the Recorder will alternate turns completing the Punnett Squares. Each group member will record the group's answers in his/her notebook. The teacher must check each answer.

Question A: Teacher Guided - use Red and Blue markers and Mat 

Cross a pure, short female plant (t) with a pure, tall male plant (T). 

1) What is the female genotype and the male genotype? 

2) Which is the dominant genotype? Which is the recessive genotype? 

3) What will result when a pure dominant is crossed with a pure recessive? 

4) What is the phenotype for each offspring? 

5) Using Probability terminology, state the combination results for the offsprings. 

Question B: Use red and blue markers and dry erase markers 

Cross a tall hybrid (Tt) with a tall hybrid (Tt) 

1) Label the male/dominate genotype and the female/recessive genotype. 

2) What is the phenotype of the offsprings? 

3) Will any pure dominant or pure recessive form from the combination? 

4) Using Probability terminology, state the combination results for the offsprings.

*** Use Black parent guinea pig (BB or Bb) and Brown parent guinea pig (bb) *** 

Question C: Use Dry Erase Markers 

Cross a Black hybrid parent with a brown parent. 

1) Label the male/dominate genotype and the female/recessive genotype. 

2) What is the phenotype of the offsprings? 

3) Will any pure dominant or pure recessive form from the combination? 

4) Using Probability terminology, state the combination results for the offsprings. 

Question D: Use Dry Erase Markers 

Cross a brown parent with a brown parent. 

1) Label the male/dominate genotype and the female/recessive genotype. 

2) What is the phenotype of the offsprings? 

3) Will any pure dominant or pure recessive form from the combination? 

4) Using Probability terminology, state the combination results for the offsprings.

Attachment Three: Assessment Sheet

Solving Genetic Puzzles Assessment Sheet 

Directions: The groups will work together to complete the sheet. Each group must sign the statement below. Staple the Assessment to the rubric. The reader will read each question to the group. The recorder will write the group's response for each question in the space provided. Remember the Punnett Square should be part of your response. All answers should be clear, detailed, and relevant.

*** Use Black Guinea Pig (BB or Bb) and Brown Guinea Pig (bb) ***

Question A: Cross a Black hybrid with a Black hybrid. 

1) Label the male/dominate genotype and the female/recessive genotype. 

2) What is the phenotype of the offsprings? 

3) Will any pure dominant or pure recessive form from the combination? 

4) Using Probability terminology, state the combination results for the offsprings.

Question B: Cross a pure, male Black parent with a Black hybrid parent. 

1) Label the male/dominate genotype and the female/recessive genotype. 

2) What will result when a pure dominant is crossed with a hybrid? 

3) What is the phenotype for each offspring? 

4) Using Probability terminology, state the combination results for the offsprings.

Question C: Cross a female, short haired dog (SS) with a male, long haired dog (ss). 

1) What is the female genotype and the male genotype? 

2) Which is the dominant genotype? Which is the recessive genotype? 

3) What will result when a pure dominant is crossed with a pure recessive? 

4) What is the phenotype for each offspring? 

5) Using Probability terminology, state the combination results for the offsprings.

Question D: The group will create a Genetic Puzzle and develop 3 to 5 questions (in same format as the above). Include a completed a Punnett Square and answers to the questions. 

Choose from: Freckles (F); No Freckles (f) / Smooth Seeds (R); Wrinkled Seeds ( r ) / Female (X); Male (Y)

Group Members Agreement Compact: 
I, _____________________, agree with the answers to the above questions. I, ___, actively participated in completing the assessment sheet.

1) Recorder's Signature: _______________________________Date: ________ 

2) Material's Signature : ________________________________Date: ________ 

3) Reader's Signature : _________________________________Date : ________

Attachment Four: Assessment Rubric

Solving Genetic Puzzles Cooperative Group Assessment - Rubric

Recorder's Name: ______________________________________ 

Material's Name: _______________________________________ 

Reader's Name: ________________________________________ 

Directions: Staple this form to the back of the Assessment sheet. Restatement of Assessment Directions: The groups will work together to complete the sheet. Each group must sign the statement below. Staple the Assessment to the rubric. The reader will read each question to the group. The recorder will write the group's response for each question in the space provided. Remember the Punnett Square should be part of your response. All answers should be clear, detailed, and relevant.

Total Points  ____________________ / 100 points

***Failure to Turn in with Assessment Sheet will result in a reduction of 20 points.***