1. Genetics terms

2. Gene: A section of DNA that codes for traits
Ex: eye color, hair color, etc…
Allele: different form of the same gene
Represented by capital and lowercase letters
Ex: blonde hair, brown hair (B or b)

3. What alleles for eye color are present in your family?
Tell the person sitting next to you…

4. Phenotype: physical appearance, expression of a gene
Genotype: combination of alleles, represented by capital or lowercase letters
Ex: BB, Bb, bb
Phenotype: physical appearance, expression of a gene
Ex: Blonde hair, brown hair, curly hair

5. Can people have a different genotype but the same phenotype?
Explain to the person sitting across from you….

6. Dominant: the version of the allele that will always show if it occurs in the genotype
Ex: (capital letters) BB or Bb
Recessive: the version of the allele that is hidden by the dominant version if both are present
Ex: (lowercase letters) bb

7. Is it possible for two parents that show a dominant phenotype to have a recessive child?
Talk about this with your entire table…

8. Which of these genotypes are heterozygous? Which are homozygous?
Heterozygous: Two different alleles (only the dominant version shows)
Ex: Bb
Homozygous: same type of alleles
Ex: BB or bb
Which of these genotypes are heterozygous? Which are homozygous?

9. If a person has a recessive phenotype is their genotype homozygous or heterozygous?
Explain to your neighbor…

10. Monohybrid: cross, or mating, between organisms that involves only 1 pair of contrasting traits.
Ex: Color (green vs yellow)
Dihybrid: cross, or mating, between organisms that involves 2 pairs of contrasting traits.
Ex: Color (green vs yellow) and Shape (round vs wrinkly)

11. In the monohybrid cross example, what % were yellow and what % were green and why? In a dihybrid cross, Why does each box have two alleles?
Explain both answers to a partner.