It’s Not as Simple as Mendel Said: A Lesson in Shamrock Genetics

Time Required: One 60-minute session
Skill Level: Beginner
Recommended Grades: 6th to 8th

In this activity, students will review the science behind 4-leaf clovers. Individual students will doodle a 3-leaf or a 4-leaf clover based on their final score in the Shamrock Memory Game, which will be played after a review of lesson materials.

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Lesson Plan


Step 1

Conduct a class discussion to refresh the rules of dominant vs. recessive trait inheritance. Be sure to include a conversation about mutations that may increase the chances of a plant's survival; extra leaves, for example, help the plant create more energy.

In addition to reviewing the vocabulary, students will need to know a little bit more about white clover, the type of clover most closely associated with 4-leaf clovers. Read and discuss this article titledThe Mysterious Genetics of the Four-Leaf Clover, then discuss the critical thinking questions below.

-Why is finding the exact gene that causes the 4-leaf mutation so difficult?
-How do you think having only 3 leaves could give the clover an advantage?
-What about a disadvantage?

Step 2

For some basic information about clovers, have the students watch this video: How Science Can Help You Find a 4-Leaf Clove

Based on the information in the video and article, ask students:

How many 4-leaf clovers do you think we should “find” in our class? How did you come to your answer?

For more information about optimum conditions for growing four-leaf clovers, see the following pages:

Recessive genes, temperature produce four-leaf clover

Clover Care

Step 3

Pair students together.

First, have them review the vocabulary words from this lesson. Feel free to write them on the board.

Step 4

Next, review the rules of the Shamrock Memory Game. Be sure to explain the score sheet and how to keep track of points earned by rolling the die with tally marks.

Allow time for students to play their game. Review the students' work. Have students adjust points earned as necessary.

Step 5

Discuss the items that plants need in order to survive: sunlight, water, nutrients, etc. This discussion is meant to help facilitate students’ allocation of points for the perfect conditions to “grow” a 4-leaf clover in the game.

Circulate through the class to help with the score sheet.

Step 6

After students have spent their points, use this key to distribute 3-leaf vs. 4-leaf clovers.

If a student has allocated points within the following ranges, they are "lucky" and make 4-leaf clovers. All other combinations earn a 3-leaf clover/shamrock.

70-80 degrees
2-3 "waterings" in 7 days
10 -12 hours of sunlight each day

Step 7

Handout the 3Doodler pens and plastics (green). Allow 5-10 minutes for students to doodle their clovers. Circle the classroom to assist students as they doodle their clovers.

Step 8

Ask students what advantages and/or disadvantages they think having the extra leaf would give the clover. Explain how the 4-leaf variant is likely a recessive trait as it occurs only 1 in 10,000 clovers.

Wrap Up

While most animals are diploid (meaning they have 2 sets of chromosomes in their cells), clover (specifically white clover) are considered to be allotetraploids. This means they have 4 copies of chromosomes in their cells! Because of this, it is difficult to determine exactly which gene or genes are responsible for the 4-leaf clover mutation. It is currently believed by many scientists to be a recessive trait. It is important to discuss the relationship between the infrequency of a 4-leaf clover and it being thought to be a recessive trait.


The teacher will assess students’ work based on the written responses on the score cards, as well as verbal responses.

Possible Extensions

Students can use their clovers as "bait" as they design Leprechaun traps based on the book, "How to Catch a Leprechaun". Students can use their clovers to help decorate the classroom. Students can "invent" and doodle a new variety of clover, then write about how the mutation helped it to be better suited to its environment.


Ted Ed Video on Mendel's Pea Plants:


  • Allele - the different forms of a gene

  • Diploid - cells that have two complete sets of chromosomes

  • Dominant - an allele whose trait always shows up in the organism when the allele is present

  • Environmental Factor - any factor that influences living things

  • Gene - a segment of DNA on a chromosome that codes for a specific trait

  • Genotype - an organism's genetic makeup or allele combination

  • Haploid - cells that have only one complete set of chromosomes

  • Heterozygous - having two different alleles for a trait

  • Homozygous - having 2 identical alleles for a trait

  • Mutation - a change that occurs in our DNA due to mistakes or environmental factors

  • Phenotype - an organism's physical appearance of a visible trait

  • Punnett Square - a square diagram that is used to predict the genotypes of a particular cross or breeding experiment

  • Recessive - an allele that is masked when a dominant allele is present

Educational Standards

Next Gen Science

Construct an explanation based on evidence that describes how genetic variations of traits in a population increase some individuals’ probability of surviving and reproducing in a specific environment.

In This Lesson

Students will understand and explain how genetic variations of traits in a population increase certain probabilities of survival and reproduction in a specific environment.

Common Core

Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.

In This Lesson

Students will review science content vocabulary for use and meaning.

Common Core

Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating an understanding of the subject under investigation.

In This Lesson

Students will research information about the genetic studies regarding the 4-leaf vs. 3-leaf clover.


Students demonstrate creative thinking, construct knowledge, and develop innovative products and processes using technology: use models and simulations to explore complex systems and issues

In This Lesson

Students will use the 3Doodler pens to visually demonstrate the 3-leaf and 4-leaf clover variants.


Students use critical thinking skills to plan and conduct research, manage projects, solve problems, and make informed decisions using appropriate digital tools and resources: Collect and analyze data to identify solutions and/or make informed decisions

In This Lesson

Students build models of the clover and can refine their work if determined that it is incorrect.


Students demonstrate a sound understanding of technology concepts, systems, and operations.

In This Lesson

Students will use the appropriate tools to create their model shamrocks or 4-leaf clovers.


Students communicate complex ideas clearly and effectively by creating or using a variety of technology to create visualizations, models or simulations.

In This Lesson

Students create models of 3-leaf or 4-leaf clovers.


Students contribute constructively to project teams, assuming various roles and responsibilities to work effectively toward a common goal.

In This Lesson

Students will work together to answer questions and build their knowledge of genetic variations.

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