Reference no: EM133416410

Questions

1. The Activate gene codes for the ACT protein. ACT is an activator protein (transcription factor) and helps regulate expression of genes involved in plant growth.

When compound X is available, it binds to ACT and causes a conformational change that is required for ACT to function.

You have plants that are homozygous wildtype for the Activate gene. As well, you have two plant lines that are heterozygous for the wildtype allele and a mutant allele of the Activate gene. The first mutant line has a nonsense mutation that is located just three codons into the Activate coding sequence. The second mutant line has an insertion encoding several nonsynonymous mutations in the compound X binding region of the ACT protein. The protein encoded by this mutant allele cannot bind compound X and changes the conformation of the wildtype protein disabling its ability to bind compound X.

You raise the three plant genotypes in two different environments, one environment in which compound X is absent and one in which there are high amounts of compound X.

Do the following:

• Draw a norm of reaction graph (see Week 6 pre-class prep) for this study if Activate was haplosufficient.

• Draw the norm of reaction graph for this study if Activate was haploinsufficient.

• Explain the difference(s) between the two graphs.

2. Anna (who produces eggs) and Syed (who produces sperm), have a child with Down's syndrome that results from trisomy of chromosome 21. Using a microsatellite sequence on chromosome 21, you run a gel. Darker bands indicate signals of twice the intensity.

If a nondisjunction event occurred in Anna during meiosis I, which lane (A, B, C, D) best fits the genotype of their child? Explain your choice, clearly identifying why that lane is correct and why the other lanes are incorrect. Assume no recombination.