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What are Punnett Squares?. Punnett Squares are used to figure out the genes and traits of offspring when the genes of the parents are known.They can also be used to find the parents genes.. First, some vocabulary to add. Genotype: genes, abbreviated with lettersPhenotype: physical traitsAllele:
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1. Punnett Squares- Day 1 Objective:
SWBAT construct and complete Punnett Squares in order to predict genetic outcomes.
Drill:1. Why are gametes haploid?
What process in meiosis makes each gamete unique?
Describe the cells made by fertilizaton.
2. What are Punnett Squares? Punnett Squares are used to figure out the genes and traits of offspring when the genes of the parents are known.
They can also be used to find the parents genes.
3. First, some vocabulary to add… Genotype: genes, abbreviated with letters
Phenotype: physical traits
Allele: forms of a gene (A or a)
Homozygous: 2 of the same gene (AA, aa)
Heterozygous: 2 different genes (Aa)
Dominant: the stronger gene; if present, it will always cover up the other gene and show dominant trait; shown with capital letters
Recessive: the weaker gene; must have 2 copies to have the recessive trait; shown with lower-case letters
4. Let’s Practice Describe the following GENOTYPES as either homozygous or heterozygous. If homozygous, specify dominant or recessive.
1. BB 4. Tt 7. ff
2. Rr 5. ee 8. AA
3. dd 6. KK 9. Hh
5. Punnett Square Steps Read the scenario. Decide on the letter you will use to represent the gene. Write out the 3 possible genotypes AND the phenotype that goes with each. Figure out the parent genotypes. Draw a Punnett Square. Write the parent genotypes on the outside. One parent at top, other parent along left side. Fill in the offspring genotypes by bringing the parent genotypes over and down. Example: Parent 1= AA Parent 2= aa