ALEX Lesson Plan


SpongeBob RoundPants? What's the Chance?

You may save this lesson plan to your hard drive as an html file by selecting "File", then "Save As" from your browser's pull down menu. The file name extension must be .html.

  This lesson provided by:  
Author:Nancy Caffee
System: Blount County
School: Blount County Career Technical Center
  General Lesson Information  
Lesson Plan ID: 32234


SpongeBob RoundPants? What's the Chance?


What are the chances of SpongeBob having kids with round pants? Working in cooperative learning groups, students explore the concept of probability. Using interactive websites, students explore the possibilities of an organism having a particular trait by completing a virtual lab using Punnett squares. Students will apply their knowledge to predict possible outcomes of the offspring of the residents of Bikini Bottom.

 Associated Standards and Objectives 
Content Standard(s):
MA2015 (2015)
Grade: 7
18 ) Use data from a random sample to draw inferences about a population with an unknown characteristic of interest. Generate multiple samples (or simulated samples) of the same size to gauge the variation in estimates or predictions. [7-SP2]

Example: Estimate the mean word length in a book by randomly sampling words from the book; predict the winner of a school election based on randomly sampled survey data. Gauge how far off the estimate or prediction might be.

SC2015 (2015)
Grade: 7
Life Science
12 ) Construct and use models (e.g., monohybrid crosses using Punnett squares, diagrams, simulations) to explain that genetic variations between parent and offspring (e.g., different alleles, mutations) occur as a result of genetic differences in randomly inherited genes located on chromosomes and that additional variations may arise from alteration of genetic information.

Insight Unpacked Content
Scientific And Engineering Practices:
Developing and Using Models
Crosscutting Concepts: Cause and Effect
Disciplinary Core Idea: Heredity: Inheritance and Variation of Traits
Evidence Of Student Attainment:
  • Identify and describe the relevant components of the model.
  • Develop a model for a given phenomenon involving the variations that arise between parent and offspring as a result of randomly inherited genes and alteration of genetic material.
  • Use a model to explain a given phenomenon involving the variations that arise between parent and offspring as a result of randomly inherited genes and alteration of genetic material.
Teacher Vocabulary:
  • Punnett square - monohybrid cross
  • Homozygous and Pure
  • Heterozygous and
  • Hybrid
  • Homologous
  • Dominant
  • Recessive
  • Models
  • Genetic variation
  • Parent
  • Offspring
  • DNA
  • Genes
  • Inheritance
  • Allele
  • Variation
  • Mitosis (introduced in Standard 2; use here for comparison to Meiosis)
  • Meiosis
  • Chromosome
  • Mutation
  • Probability
  • Gregor Mendel
  • Mendel's laws
  • Sexual reproduction
  • Asexual reproduction
  • Sperm
  • Egg
  • Zygote
Students know:
  • Chromosomes are the source of genetic information.
  • Organisms reproduce, either sexually or asexually, and transfer their genetic information to offspring.
  • Variations of inherited traits from parent to offspring arise from the genetic differences of chromosomes inherited.
  • In sexual reproduction, each parent contributes half of the genes acquired (at random) by the offspring.
  • Individuals have two of each chromosome, one acquired from each parent; therefore individuals have two alleles (versions) for each gene. The alleles (versions) may be identical or may differ from each other.
Students are able to:
  • Construct a model for a given phenomenon involving the differences in genetic variation that arise from genetic differences in genes and chromosomes and that additional variations may arise from alteration of genetic information.
  • Identify and describe the relevant components of the model.
  • Describe the relationships between components of the model.
  • Use the model to describe a causal account for why genetic variations occur between parents and offspring.
  • Use the model to describe a causal account for why genetic variations may occur from alteration of genetic information.
Students understand that:
  • During reproduction (both sexual and asexual) parents transfer genetic information in the form of genes to their offspring.
  • Under normal conditions, offspring have the same number of chromosomes (and genes) as their parents.
  • In asexual reproduction: Offspring have a single source of genetic information and their chromosomes are complete copies of each single parent pair of chromosomes. Offspring chromosomes are identical to parent chromosomes.
  • In sexual reproduction: Offspring have two sources of genetic information that contribute to each final pair of chromosomes in the offspring because both parents are likely to contribute different genetic information, offspring chromosomes reflect a combination of genetic material from two sources and therefore contain new combinations of genes that make offspring chromosomes distinct from those of either parent.
AMSTI Resources:
AMSTI Module:
Studying the Development and Reproduction of Organisms

Local/National Standards:

Develop and evaluate inferences and predictions that are based on data

Grades 6–8 Expectations: In grades 6–8 all students should– 

  • use observations about differences between two or more samples to make conjectures about the populations from which the samples were taken;
  • make conjectures about possible relationships between two characteristics of a sample on the basis of scatterplots of the data and approximate lines of fit;
  • use conjectures to formulate new questions and plan new studies to answer them.

Understand and apply basic concepts of probability  

Grades 6–8 Expectations: In grades 6–8 all students should– 

  • understand and use appropriate terminology to describe complementary and mutually exclusive events;
  • use proportionality and a basic understanding of probability to make and test conjectures about the results of experiments and simulations;
  • compute probabilities for simple compound events, using such methods as organized lists, tree diagrams, and area models

Primary Learning Objective(s):

Students will be able to make predictions using the Punnett square.

Additional Learning Objective(s):

Describe terms related to the study of genetics.

Practice converting fractions to percentages.

Interpret the results of a cross between two heterozygous  and two homozygous parents.

Apply knowledge of the Punnett square by solving problems in a monohybrid cross.

Investigate probability by collecting and analyzing data.

Write a hypothesis on the predicted outcome of an event.

 Preparation Information 

Total Duration:

61 to 90 Minutes

Materials and Resources:

Download and print the student worksheet and teacher key for Bikini Bottom Genetics.

Download and print the student worksheet and teacher key for Bikini Bottom Genetics 2.

One coins per group (Pennies work well)

Student Data Sheet (One per student) Located in the attachments

Technology Resources Needed:

Computer with video projector

Interactive Whiteboard or Interactive Tablet (Optional)

Document Camera (Optional)

Computer lab with Internet access (Optional)

Java must be installed or enabled

Interactive labs require the most recent version of the Flash plug-in.


Students should be familiar with the following vocabulary prior to the lesson

Punnett square,  genotype,  heterozygous,   homozygous, phenotype,  carrier of a trait, dominant allele, recessive allele, genetics, heredity, traits, genes, chromosomes, monohybrid cross,  dihybird, Gregor Mendel, incomplete dominance, sex-linked traits, Mendel's Law of Dominance, Law of Segregation, Law of Independent Assortment

Historical information on Gregor Mendel’s studies can be found in the website about “The Father of Genetics.”

The class may need to review the background information on Mendel’s laws and the use of Punnett squares provided in this “Genetics” PowerPoint.

Divide students into diverse cooperative learning groups of four. Cooperative learning groups should be blended with various ethnicities including both girls and boys. Higher achieving students should be combined with the lower achieving students.

  1. Working in cooperative learning groups, students explore the concept of probability by conducting a coin toss. Instructions for the coin toss are included on the “Coin Probability Worksheet” included in the attachments.
  2. Using an interactive website, Virtual Lab Punnett Squares, students predict the outcome of the monohybrid cross.  Students can complete the virtual lab individually in a computer lab or as a group using an interactive whiteboard and a digital projector.
  3. Students groups explore “The Probability of Genetics” through an interactive website. Students click on the word to find the meaning and hear the word pronounced. After exploring the website, student groups will also complete the online practice quiz included in the website.
  4. Working in diverse cooperative learning groups, students will apply knowledge of Punnett squares by determining the chance of SpongeBob's children having round pants by completing the Bikini Bottom Genetics activities provided in the background section of this plan. As time permits, one or both of the activities may be used according to how much practice the students need.
  5. Each group will share an assigned section of the Bikini Bottom Genetics with the class. They can present their information explaining the probability of the offspring having a particular trait using the document camera, the interactive whiteboard, or a regular whiteboard.

**Some files will display in a new window. Others will prompt you to download.

Assessment Strategies

SpongeBob Genetics Quiz

Sample test questions and practice using Punnett squares and Mendel’s Laws of Segregation


As an extension for students who understand the concept of Punnett squares, challenge them with the Bikini Bottom Incomplete Dominance worksheet. 

As an extension for students who have mastered the monohybrid cross, the “Multiple Allele Traits in Chickens” activity provides practice for determining the outcome for multiple alleles.



An online tutorial is provided to practice using Mendel’s laws of genetics and Punnett squares

This website offers a PowerPoint with practice questions reviewing Mendel’s law of segregation.

Each area below is a direct link to general teaching strategies/classroom accommodations for students with identified learning and/or behavior problems such as: reading or math performance below grade level; test or classroom assignments/quizzes at a failing level; failure to complete assignments independently; difficulty with short-term memory, abstract concepts, staying on task, or following directions; poor peer interaction or temper tantrums, and other learning or behavior problems.

Presentation of Material Environment
Time Demands Materials
Attention Using Groups and Peers
Assisting the Reluctant Starter Dealing with Inappropriate Behavior
Be sure to check the student's IEP for specific accommodations.