This lesson was adapted from a lesson by Katie Ward of Aragon High School in San Mateo. After trying Katie’s version with my students, I found several other similar activities on the web. For instance, see the Making Babies lab written by Kevin Hartzog of Thurgood Marshall Academic High School. Kevin Hartzog's website Stars and Seas is extraordinary! With lots of other great lessons and ideas. Also recommended is this Making Babies lab from Friends Academy .
For information about Mendelian genetics, see:
- The Wikipedia articles on Gregor Mendel and Mendelian inheritance are both excellent short summaries.
- An excellent genetics tutorial is available from Dr. Dennis O’Neil of Palomar College.
- MIT has a good online genetics textbook chapter targeted for college level genetics courses.
- The Biology Project at the University of Arizona also had a good series of online genetics resources and tutorials.
- To go right to the source, Mendel’s original 1865 article with reference materials and commentary from classroom teachers can be found at MendelWeb.
For more information on the inheritance of human traits such as eye color, hair color, and tongue rolling, see:
- The Eye Color Calculator from the Tech Museum of Innovations’ online genetics exhibit is very fun with good genetics background information. In addition, their “Ask a geneticist” area contains great Q&A about other human traits such as hair color, addiction, ADHD, genetic diseases and more. Do your students have a question that you can’t answer? Post a question!
- For a searchable database of human genes and relevant scientific studies, John Hopkins has a fantastic resource, the Online Mendelian Inheritance in Man website.
- The Wikipedia article on dominance relationships including a short list of traits governed by simple dominance.
- Bill Kendrick created a very fun “Gene Machine” that predicts your genotype based on inputting the phenotypes of yourself, your mother and your father.
2. A typical cell of any organism contains genetic instructions that specify its traits. Those traits may be modified by environmental influences. As a basis for understanding this concept:
b. Students know sexual reproduction produces offspring that inherit half their genes from each parent.
c. Students know an inherited trait can be determined by one or more genes.
d. Students know plant and animal cells contain many thousands of different genes and typically have two copies of every gene. The two copies (or alleles) of the gene may or may not be identical, and one may be dominant in determining the phenotype while the other is recessive.
2. Mutation and sexual reproduction lead to genetic variation in a population. As a basis for understanding this concept:
a. Students know meiosis is an early step in sexual reproduction in which the pairs of chromosomes separate and segregate randomly during cell division to produce gametes containing one chromosome of each type.
b. Students know only certain cells in a multicellular organism undergo meiosis.
c. Students know how random chromosome segregation explains the probability that a particular allele will be in a gamete.
d. Students know new combinations of alleles may be generated in a zygote through the fusion of male and female gametes (fertilization).
e. Students know why approximately half of an individual's DNA sequence comes from each parent.
f. Students know the role of chromosomes in determining an individual's sex.
g. Students know how to predict possible combinations of alleles in a zygote from the genetic makeup of the parents.
3. A multicellular organism develops from a single zygote, and its phenotype depends on its genotype, which is established at fertilization. As a basis for understanding this concept:
a. Students know how to predict the probable outcome of phenotypes in a genetic cross from the genotypes of the parents and mode of inheritance (autosomal or X-linked, dominant or recessive).
b. Students know the genetic basis for Mendel's laws of segregation and independent assortment.
c. * Students know how to predict the probable mode of inheritance from a pedigree diagram showing phenotypes.