♦ ♦ ♦ Punnet Squares Flashcards
How do you set up a basic punnet square?
Explain where each parent’s information must go and how the square is structured.
On the top of the punnet square is one parent’s phenotype and the genotype in parenthesis ex. (Yb). On the left side of the punnet square is the other parent’s phenotype and the genotype in parenthesis x. (bb)
The gene in gamete 1 and gamete 2 are put on the left and top side of the punnet square. The 1st one is far left or top.
The boxes have the combined genotype based on the edges of each cube in the punnet square
What are the genotypes for male and female?
What happens when gender and other genes must be considered in the punnet square? How is the genotype formatted?
Male - XX Female - XY
If gender and other genes are considered then each chromosome allele (X or Y) is paired with the other gene.
ex. If G represents green and b represents brown and green is dominant over brown and this is contingent on gender then an example genotype and phenotype could be:
Male Green and Female Green
(XG, Yb) and (XG, XG)
Don’t forget to determine the gender and phenotype of the offspring.
What is the definition of heterozygous?
Give an allele example
What is the definition of homozygous?
Give an allele example
If an organism is heterozygous then it means that it has one dominant gene and one recessive, the dominant gene prevails and becomes the phenotype
Ex. allele (Y, b)
If an organism is homozygous then it has two dominant genes, the dominant gene prevails and becomes the phenotype. It is also known as a purebred.
Ex. allele (Y, Y)
What happens when a gene is carried on a chromosome?
How might it be represented?
What would be an example of this genetic problem?
When a gene is carried on a chromosome then it means it is related to gender instead of other problems when you need to determine the gender of the offspring.
It can be represented by a subscript ex. XN
This can be an example of a problem involving hemophilia, where the mutation for hemophilia (or lack of blood regulation genes) lies on the X chromosome.
