This document is a comprehensive study guide for the Mouse Genetics Gizmo simulation by ExploreLearning. It explores the principles of heredity and genetic inheritance using mice as a model organism. The guide includes interactive activities that allow users to breed mice with different fur colors and analyze the resulting offspring’s phenotypes and genotypes. Key topics covered include dominant and recessive alleles, Punnett squares, and the basics of genetic inheritance. The document is structured into sections that guide users through experiments, predictions, and analyses of genetic outcomes. It serves as an educational resource for students studying genetics and heredity in a hands-on manner.
Name: Zach Joseph Section: 6
Student Exploration: Mouse Genetics (One Trait)
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: allele, DNA, dominant allele, gene, genotype, heredity, heterozygous, homozygous, hybrid,
inheritance, phenotype, Punnett square, recessive allele, trait
Gizmo Warm-up
Heredity is the passage of genetic information from parents to offspring.
The rules of inheritance were discovered in the 19
th
century by Gregor
Mendel. With the Mouse Genetics (One Trait) Gizmo™, you will study how
one trait, or feature, is inherited.
1. Drag two black mice into the Parent 1 and Parent 2 boxes. Click Breed
to view the five offspring of these parents.
What color are the offspring? They’re grayish - black
The appearance of each mouse is also called its phenotype. In this lab, we will be investigating the fur
color trait, so the phenotype = fur color.
2. Click Clear and drag two white mice into the parent boxes. Click Breed several times. What is the
phenotype of the offspring now?
All the mice are white
3. Do you think mouse offspring will always look like their parents? Explain:
Yes because they both have the same color fur and size
Activity A:
Patterns of
inheritance
Get the Gizmo ready:
● Click Clear.
● Drag a black mouse and a white mouse into the
parent boxes, but don’t click Breed yet.
Question: What patterns are shown by offspring traits?
1. Predict : What fur color(s) do you think the offspring of a black mouse and a white mouse will have?
The offspring color of both the white mouse and back mouse
2. Observe : Click Breed several times. What do you see?
The mouses are still black
3. Observe : Drag two offspring into the Holding Cages. These mice are called hybrids because their parents
had different traits. Click Clear, and then breed the two hybrids.
Reproduction for educational use only. Public sharing or posting prohibited© 2020 ExploreLearning™ All rights reserved
What do you see now? One of the 5 mouses turned white
4. Experiment : Turn on Show statistics. Click Breed until there are 100 offspring.
How many offspring were black? 96 How many were white? 29
Activity B:
Genetics basics
Get the Gizmo ready:
● Click Clear.
● Drag a black mouse and a white mouse into the
parent boxes.
Introduction: Inherited traits are encoded on a molecule called DNA (deoxyribonucleic acid). Genes are
segments of DNA that control a particular trait. Most genes have several different versions, or alleles. The
genotype is the allele combination an organism has, written using a combination of letters.
Question: How do alleles determine fur color?
1. Observe : Turn on Show genotype. Move your cursor over a mouse to see its genotype.
A. What is the genotype of the black parent? FF White parent? ff
These mice are homozygous for fur color, meaning both alleles are the same.
B. Click Breed. What is the genotype of the offspring mice? Ff
These mice are heterozygous for fur color, meaning the alleles are different.
2. Analyze : Dominant alleles are always expressed when present. Recessive alleles are not expressed
when the dominant allele is also present. Look at the two alleles for fur color.
A. Which allele is dominant, and which fur color does
it produce?
Black
B. Which allele is recessive, and which fur color does
it produce?
White
3. Predict : Place two of the Ff offspring into the Holding Cages. Click Clear, and then place them into the
parent boxes.
A. Which allele(s) could the offspring inherit from
parent 1?
Black fur and be tall
B. Which allele(s) could the offspring inherit from
parent 2?
White fur and be small
C. What are the possible genotypes of the offspring? Ff or ff
4. Experiment : Click Breed several times, and look at the genotypes of the offspring. Did you find all the
predicted genotypes? Explain.
Yes, because the only 2 outcomes could just be Ff or ff for white fur or black fur
Activity C:
Modeling
inheritance
Get the Gizmo ready:
● Click Clear.
● Drag a black mouse and a white mouse into the
parent boxes.
Question: How do scientists predict the genotypes of offspring?
F F
1. Model: Scientists use a Punnett square to model the different possible
offspring genotypes from a parent pair. The parent genotypes are written
across the top and side of the square, as shown. The four possible
offspring genotypes are then filled in.
f Ff Ff
f Ff Ff
The first square is filled in for you. Fill in the remaining squares.
A. What are the possible genotypes of these offspring? ff
B. What % of the offspring is expected to have black fur? 50%
C. What % of the offspring is expected to have white fur? 50%
2. Experiment : Click Breed several times.
Were your predictions correct? No
3. Model : Use the Punnett squares below to model each parent combination. After filling in each Punnett
square, predict the percentages of black and white offspring.
Parent 1: Heterozygous black (Ff)
Parent 2: Heterozygous black (Ff)
Parent 1: Heterozygous black (Ff)
Parent 2: Homozygous white (ff)
f F f f
F Ff FF F Ff Ff
f ff Ff f ff ff
Predicted % black offspring: 75% Predicted % black offspring:
50%
Predicted % white offspring: 25% Predicted % white offspring: 50%
4. Experiment : Now you will run two experiments to test the predictions you made in #3.
a. First experiment: cross two Ff mice (remember- to obtain Ff mice, breed an FF mouse to an ff
mouse, place two Ff offspring into the holding cages, click Clear, and then drag the Ff mice into the
parent boxes.) Turn on Show statistics and Show as approximate percentage, and breed ~ 500
offspring. Record the resulting percentages in the table below.
End of Document
389
