The creation of a Punnett Square and a Pedigree chart are used to show the
passing of traits and the possibilities that the offspring might have. After
making a cross using a Punnett Square, you can relate your vocabulary to finding
the possibilities for offspring and look at the different ways to cross.
passing of traits and the possibilities that the offspring might have. After
making a cross using a Punnett Square, you can relate your vocabulary to finding
the possibilities for offspring and look at the different ways to cross.
After looking at the cross of the two parents, we can see the possible outcomes for the offspring.
DOMINANT: Looking at the alleles, the dominant gene is always the uppercase letter. In this case, it would be A, representing brown hair which is a dominant trait.
RECESSIVE: Looking at the alleles, the recessive gene is always the lowercase letter. In this case, it would be a, representing blonde hair which is a recessive trait.
HOMOZYGOUS: You have to look at the pair of alelles to see if they are the same or different. With this cross, one of the parents are homozygous dominant because both alleles are dominant AA. But in future crosses, there can be AA or aa.
HETEROZYGOUS: You have to look at the pair of alleles to see if they are the same of different. With this cross, one of the parents are heterozygous because there are two different alleles, dominant and recessive.
GENOTYPE: The genotypes of this cross would be 2 AA and 2 Aa. To find the genotype, you must looking at all of the outcomes and add up all of the similar pairs.
PHENOTYPE: The phenotype of this cross would be 4 with brown hair. To find the phenotype, you use the genotypes that you found in order to see what trait will show up with each pair.
INCOMPLETE DOMINANCE: Although it is not shown in this punnett square, incomplete dominance is a blend of two colors- like mixing a white flower and a red flower with a result of a pink flower.
CO-DOMINANCE: This is not shown in the punnett square above but it is when there are spots of color, and not solid. This can be found in breeding cows and not getting a solid mix, but having spots of another color.
DOMINANT: Looking at the alleles, the dominant gene is always the uppercase letter. In this case, it would be A, representing brown hair which is a dominant trait.
RECESSIVE: Looking at the alleles, the recessive gene is always the lowercase letter. In this case, it would be a, representing blonde hair which is a recessive trait.
HOMOZYGOUS: You have to look at the pair of alelles to see if they are the same or different. With this cross, one of the parents are homozygous dominant because both alleles are dominant AA. But in future crosses, there can be AA or aa.
HETEROZYGOUS: You have to look at the pair of alleles to see if they are the same of different. With this cross, one of the parents are heterozygous because there are two different alleles, dominant and recessive.
GENOTYPE: The genotypes of this cross would be 2 AA and 2 Aa. To find the genotype, you must looking at all of the outcomes and add up all of the similar pairs.
PHENOTYPE: The phenotype of this cross would be 4 with brown hair. To find the phenotype, you use the genotypes that you found in order to see what trait will show up with each pair.
INCOMPLETE DOMINANCE: Although it is not shown in this punnett square, incomplete dominance is a blend of two colors- like mixing a white flower and a red flower with a result of a pink flower.
CO-DOMINANCE: This is not shown in the punnett square above but it is when there are spots of color, and not solid. This can be found in breeding cows and not getting a solid mix, but having spots of another color.
CARRIER: In this pedigree chart, we see the passing of the dominant trait of brown eyes. Although someone might not show brown eyes, they can pass the trait if they are heterozygous brown eyes to their offspring, which might result in their child having a light colors eye, which is a recessive gene.