Barbara has curly hair. Her genotype for this trait is CC. What do you infer from this?
She has a curly hair gene that produces the CC allele. A person with this genotype is homozygous recessive for both genes and will have curls. A heterozygote (Cc) would be able to produce either curl or straight strands of hair, but not both at the same time.
What are other traits in which Barbara could potentially show a different phenotype than her genotype?
What does this tell us about how genetics work?
If you were asked to explain any one of these questions without spoiling the content on your blog post, what might you say?
How do we know who’s right if there is a disagreement between two people who disagree on whether they share genetic material?
If it turns out that the other person is not actually related to you — but they share some of your genes, can we still say that they are genetically similar?
If the two people were relatives who disagreed about whether or not they shared genetic material, how might their disagreement be resolved?
Barbara’s curly hair gene is one way that she could potentially show a different phenotype than her genotype.
What does this tell us about genetics?
It tells us that there must be at least one more factor involved in determining what phenotype someone will have because it cannot just depend on the individual’s genotype and parents’ allele combinations.
This leads many researchers to believe that environmental factors play an important role in distinguishing phenotypes from genotypes.