Genetics Activity - Create The Kids

To Prepare:

1. First do the Punnett's Square Activity - Shows Mendel's Genetics to learn about dominant, recessive and mixed hybrid traits. Students should understand that each trait has two alleles. With a dominant trait like freckles, if someone has freckles they can be a pure dominant freckled person (FF) or a mixed hybrid freckled person (Ff) and both ways the freckles will show. Only recessive traits, like no freckles need to be pure to show up at all (ff).

*Please note to students that not all traits are passed on this simply. Simple dominant/recessive traits like these are called Mendelian traits.

2. To Create the Kids, students will be using a Punnett’s Square introduced in the Genetics for Kids Mini-Lecture. This simple chart breaks up the 2 possible alleles of the parents and crosses each so you can see what the possible offspring combinations will be.

Activity Goals:  Chart out the kids of parents with pure, homozygous traits and also mixed hybrid traits.

Procedures:

1. Give the students the following information to start.

Here are the Traits to work with today:

• Freckled Face = F, No Freckles = f
• Big Eyes = E, Small Eyes = e
• Hazel Eyes = B, Blue Eyes = b
• Kinky Hair = H, Straight Hair = h

It’s easier to start with pure, homozygous traits (both alleles for each gene are identical):

Mom is: Dominant freckled face, Recessive small eyes, Recessive blue eyes, and Recessive straight hair.

Dad is: Recessive no freckles, Dominant big eyes, Dominant hazel eyes, and Dominant kinky hair.

Their Genotypes are: Mom: FF ee bb hh Dad: ff EE BB HH

Their Phenotype is: Mom: freckled face, small eyes, blue eyes, and straight hair.

Dad: no freckles, big eyes, hazel eyes, and kinky hair.

Because they are pure (homozygous), all their kids will be mixed hybrids for these traits. They will all have the same genotype and phenotype for these traits. Work it out on a Punnett’s square. Create the kids!

2. Use the worksheet attached below to work out the resulting children, Have the kids write out their genotype (letter codes) and phenotype (words describing them). Then have them draw them!

3. If you want to go on and try another Combination (for older kids), try creating the kids of parents with mixed Hybrid traits. The results are interesting.

If Mom is: Mixed hybrid freckled face, Recessive small eyes, Recessive blue eyes, and Recessive straight hair.

Dad is: Recessive no freckles, Mixed hybrid big eyes, Mixed hybrid hazel eyes, and Mixed hybrid kinky hair.

Their Genotype is now: Mom: Ff ee bb hh Dad: ff Ee Bb Hh

Their Phenotype is still: Mom: a freckled face, small eyes, blue eyes, and straight hair.

Dad: no freckles, big eyes, hazel eyes, and kinky hair.

Now all their dominant traits are mixed hybrids (one allele is dominant and one allele is recessive), their kids will be a mix of traits. You can work out what they will be with a Punnett’s square. This show’s the 4 possible genotypes.

Results:

In the Punnett's square mix mom's two sets of alleles: Febh and febh with Dad's:fEBH and febh

Resulting 4 genotypes: FfEeBbHh, ffEeBbHh, Ffeebbhh, ffeebbhh

This shows the 4 possible phenotypes.

• One will have a freckled face, big eyes, hazel eyes, and kinky hair.
• One will have no freckles, big eyes, hazel eyes, and kinky hair.
• One will have a freckled face, small eyes, blue eyes, and straight hair.
• One will have no freckles, small eyes, blue eyes, and straight hair.