Genetic Traits You Can Talk About in Class

When I taught high school biology we would always have to cover the genetics of "Pea" plants because of the monk "Gregor Mendel" that essentially founded the field of genetics. His work with garden peas tracked traits such as wrinkled seed as compared to smooth seed and other traits. His work was the groundwork for understanding how some traits are dominant and some are recessive. In a classroom today we still cover his work and at the college level we did experiments with fruit flies. This was a lot of fun and very interesting. Some high schools will do similar experiments.

When we discuss genetics, it is natural to talk about human characteristics such as blood type, eye color, hair color etc. Sometimes you have to be very careful in your discussions because the children in your class may not actually be the child of both the parents they think are their parents. You could have a child that actually has the genetic material from a past boyfriend or girlfriend, a deceased father or mother etc. Generally I would start off the discussion saying that "Every Case Is Different" and you should not think something is wrong with your family if the genetics seems wrong. There are changes that can happen in the genetic code that will cause variations and some genetic traits seem to skip generations. Once this disclaimer has been said you can proceed a bit more safely.

We would talk about "Widows Peak" which is a trait where the hairline comes across the forehead and dips downward into a point at the center. Some people have "Widows Peak" and some do not. We would talk about the ability to curl your tongue. (This is curling length wise.) About 50% of the population can do this and the others can't . We would talk about "Hairy Middle Finger" which is where the middle finger of both hands has quite long and visible hair growing on the back side. (We would joke a bit about this because you would not want to simply hold up this finger alone and look at it since it might look like an obscene gesture, which then would cause some students to want to do this.) (Don't use the "hairy middle finger" trait if you feel uncomfortable with talking about it or with younger children.) We would talk about the "Attached" and "Unattached" earlobes. Some people have ear lobes that seem to go directly into their head at the bottom of the ear, others have a big area that hangs down and makes a great location for ear rings.

I also would have a set of color blindness cards and would ask the students to tell me what numbers they see on the cards. This would sometimes find a student that was red / green color blind. (Note: my son is red / green color blind.) You can now find these color blind tests on the internet. At one time we would do blood typing in class, but with great concern about the spread of disease, we normally would not conduct that type of test unless it was conducted by the nurse which could come to the classroom. It is more likely that the nurse would not want to do this test these days either. There are forms that would need to be signed, age requirements, and confidentiality issues now with any such test.

Students have a great deal of fun doing the tongue curl test and get a chance to stick their tongue out at the teacher and each other. They look at the ear lobes of each other etc. Since these kinds of checks are not as personal as a blood test they often create very little (if any) controversy in the classroom. You can use such discussions as a springboard to other genetic discussions. Be careful, you can get into dangerous territory quickly. As a teacher you want to give students factual information but it is not your task to reveal defects in their family heritage.

I have had a few cases where I was asked serious genetic questions from students where a member of their family had a serious genetic disease and they were concerned that they would have the trait. In such cases I would certainly suggest that they talk to their physician and that he or she would in some cases be able to perform tests to check for a specific genetic trait.

Families today are often made up of groups that are the result of multiple marriages and with genetics we are talking about traits that are passed on from the biological combination of the male and female chromosomes not by simply being stepchildren etc. In part the complexity of family units today leads to more controversy in genetic discussions. Children that are stepchildren in a family unit are "no less" a part of that family simply because they are not completely genetically the result of the parental "units" they are presently living with at the time.