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 Ratings
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| Reviewed: |
Feb 18, 2012 by Biology Editorial Board |
| Overview: |
This site introduces students to the Punnett square as a way to predict the offspring of a cross. The sire provides a simple shockwave animation that introduces the use of a Punnett square to determine offspring ratios in monohybrid and dihybrid crosses. Concepts are explained and illustrated, and then students are challenged with multiple choice questions the require them to apply the concepts to a new situation. Multiple monohybrid problems and one dihybrid problem are posed. |
| Learning Goals: |
The goal of this material is to learn how to use a Punnett square to predict the phenotypes of offspring. Users will learn the meaning of genotype, homozygous, heterozygous, hybrid, dominant allele, recessive allele, Punnett square, and dihybrid cross. |
| Target Student Population: |
This material is appropriate for high school biology students, and as a review for undergraduate level students. |
| Prerequisite Knowledge or Skills: |
Students should understand basic genetic vocabulary such as: dominant, recessive, trait. And introduction to Mendelian genetics will help users better understand the material. |
| Type of Material: |
The material at this site is presented as an interactive lesson/tutorial. |
| Recommended Uses: |
This tutorial can be used for individual study in the classroom, as homework, or as a classroom demonstration. The material provides good practice for students that have just learned about using genotypes to make predictions for simple crosses. |
| Technical Requirements: |
This site requires use of Abobe Shockwave player. |
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| Strengths: |
- The concepts are explained clearly and in a logical progression
- Clear presentation with no ambiguous statements or questions
- Has embedded questions to test student understanding that give feedback on incorrect answers
- Information is accurate
- Mono- and dihybrid crosses are addressed
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| Concerns: |
- The activity does not explain how the Punnett square relates to the biology, so students may learn to use the Punnett square algorithmically rather than achieving a deeper understanding
- Starts with an example using chickens, and then switches suddenly to using lemmings with no explanation for the switch in organism
- The yellow chicken phenotype is not clearly shown
- There is no explanation for how the genotypes for the various animals were determined
- If there was useful information to use to guide the selection this exercise would be much better
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Potential Effectiveness as a Teaching Tool |
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| Strengths: |
- The clarity and progressive nature of the activity should make it easy for students with good reading skills to progress readily
- Students receive good feedback when they answer questions
- Material includes some interactivity
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| Concerns: |
- There is a lot of text, so students with weak reading skills may need assistance
- While there is a least a little rationale for wanting a phenotype in the chicken cross, the lemming crosses have arbitrary goals
- All of the Punnett squares are done for the student, they sometimes guess what goes in the squares, but they never set one up, or are tested on what alleles go on the sides
- The extension from a monhybrid cross to dihybrid cross is not simple, and the culminating activity of a dihybrid cross is not properly prepared, as that is the only dihybrid cross provided
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Ease of Use for Both Students and Faculty |
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| Strengths: |
- Shockwave video should run well on both Mac and PC systems
- Simple controls that are clearly labeled
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| Concerns: |
- There is no way for a teacher to move freely back and forth in the activity, so its use as a demonstration tool is somewhat limited
- Uses Shockwave, which requires installation of a plugin that many people no longer use or know about
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