Science Homework Help

1, The drug Plavix requires the enzyme CYP2C19 to take it from the prodrug form to the drug form (enzyme A

below) and it requires the enzyme CES1 to convert it from active to inactive (enzyme 1 below). The active form of the drug is effective in preventing blood clots but is toxic in higher doses. Individuals with a mutation in this CES1 gene produce a version of CES1 that is not functional. You are a physician trying to determine the dosage of Plavix for a patient who is homozygous for the mutated version of the gene. What should you do?

• Decrease the normal dosage because they are making too much of the drug
• Increase the normal dosage because they are making too much of the toxic endproduct
• Increase the normal dosage because they are not making enough of the toxic endproduct
• (Choose another drug as the individual will likely suffer from too much toxicity? my guess)

2, In pea plants, yellow peas (Y) are dominant to green (y) and round peas (R) are dominant to wrinkled (r). Two pea plants were crossed, one with yellow round peas and one with green wrinkled peas. What were the genotypes of the parents?

• The yellow round was YYRR and the green wrinkled was yyrr
• The yellow round was YyRr and the green wrinkled was YyRr
• The yellow round was yyrr and the green wrinkled was YYRR
• The yellow round was YYrr and the green wrinkled was yyRR

3, When Mendel crossed a plant with smooth green peas and a plant with wrinkled yellow peas, what did he find?

• Color and shape of pea are linked (if you have a smooth pea it has to be green)
• Color and shape of pea are not linked (if you have a smooth pea, it can be green or yellow)
• Only yellow peas produce leaves
• Only smooth peas produce leaves

4, A cross is performed between a plant with genotype TtYy and a plant with genotype Ttyy. T refers to height (tall) and Y refers to color (yellow or white). If the two genes independently assort, what is the probability, expressed as a percent, that the offspring will be heterozygous for the height gene?