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Lesson Plan Industry Sector
Agriculture & Natural Resources

Lesson Plan Originally Created By: Bonnie Baxter

Dominant & Recessive Traits

Part of Unit: Basic Animal Genetics

Lesson Plan Overview / Details

This lesson will cover the principles of dominant and recessive traits, using Punnett Squares; specifically monohybrid crosses. Prior to this lesson students should already have covered curriculum in genotype and phenotype.

Lesson Time

Dominant & Recessive Traits
20 Minutes
Punnett Squares
40 Minutes

Objectives and Goals

  • Differentiate between dominant and recessive traits.
  • Display how to correctly set up and fill out a Punnett Square and/or Monohybrid Cross.
  • Understand how to determine phenotypic and genotypic ratios, using Punnett Squares.
  • Emphasize how animal genetics is pertinent to production agriculture.

Activities in this Lesson

  • Class will begin to the song, "Who's your daddy?" by Toby Keith. Greet your students at the door with an index card and tell them to quickly sit down, "So we can play who's your daddy!" Display the following PowerPoint and be sure that all students are seated quickly with an index card and pen in hand. Begin the PowerPoint once all students are seated. Tell them they will only have 15 seconds per slide and that they should pay close attention. *Hypothetically, students will tend to answer each of the questions with the most logical answer; matching offspring with a parent of the same phenotype. Once students have completed questions 1-5, have them trade index cards with a neighbor. (Remember: they should have used a pen to eliminate any answer changes.) After trading cards with a neighbor, explain that each corner of the room represents a letter answer. A's in one corner, B's in another, C's in another and D's in another corner. Review question number one and have each student stand in the corner of the answer listed on the index card they are grading. (If they have another student's card they will be more comfortable sharing the answers written... high school students don't generally like to go out on a limb and share their own answer, if their not sure it's correct.) It will be fun for you and the students to see the assumed answers of each, followed by the actual answers! Collect the cards to enforce the validity of the lesson and grade as a credit/no credit assignment. If they attempted the activity they will get credit, regardless of their actual score.

    Resources and Materials

    • Who's your daddy? [ Download ] Who's your daddy? Game with Answers
    • Who's your daddy? Toby Keith Song [ Go to Site ] Access to song clip to play at beginning of game.
  • After the "Who's your daddy?" activity the students will be very curious why the offspring don't look like the parent they marked on their index card. This will lead you into a discussion about genetics and dominant and recessive traits. Use to following PowerPoint as an instructional tool to: 1) Review Genotype & Phenotype, 2) Explain Dominant & Recessive, 3) Model Punnett Squares.

    Resources and Materials

    • Dominant vs. Recessive, Punnett Sq.'s [ Download ] PowerPoint presentation to be used with Introduction to Punnett Squares Handout
  • Have students follow along with this handout as you model the use of Punnett Squares on the PowerPoint. Demonstrate and model in a way that allows student participation. For example, "Ashley, is this a homozygous x homozygous or homozygous x heterozygous cross?" Complete number's 1-3 with students.

    Resources and Materials

    • Intro to Punnett Sq.'s and Notes [ Download ] User friendly review notes, intro. notes and introduction to Punnett Squares.
  • Page 3, #4-6, of Introduction to Punnett Squares Handout (above) is an opportunity to assess the students retention of genetic crosses via a Punnett Square Challenge! Have students first attempt page three on their own. Then allow them to share with a partner. While they are sharing, prepare the three problem sets on the board. (Or if you are really time efficient, do it before class!) Call up partners to complete a Punnett Square in front of the class, on the board. Explain that results can be expressed as ratios, fractions, decimals or percents.

  • In the last five minutes of class have the students brainstorm ideas of why they think this information might be important in the agriculture industry. List ideas on the board and discuss. For example: Cattle with out horns are more convenient for producers to raise. You can fit more cattle side by side at a feeder and worry less about carcass damage from fighting. This could also segue into other units, such as Effects of Technology on Agriculture, specifically Artificial Insemination and EPD's.

Assessment

Assessment Types:
, Practice Problems,

Collect HW the following day.  It is to be graded and used as an assessment tool.  By grading the HW you will quickly learn what PS problems to revisit up on the board as a class.  Choose a variety of these PS problems to use as a quiz to finish the unit, or use the pre-made quiz attached.

  • Punnett Sq. Homework Assignment Punnett Sq. Homework Assignment [ Download ] Assessment tool with a variety of Punnett Square practice problems.
  • Genetics Quiz Genetics Quiz [ Download ] Assessment tool for completion of basic genetics unit.