Transcript 2) Homework
Nutrition and Gene Expression Homework assignments on mutations Feb 5, 2015 THE CONSEQUENCES OF MUTATIONS: Homework assignment How is each mRNA sequence translated? For each 24-base mRNA sequence, predict how it will be translated by the ribosomes. -For each sequence, there is a SINGLE base that is different from sequence #1. What is the product in each case? -How would the biochemical properties of each product be different, when compared to sequence #1? (You will need to use the table of codons, to determine which amino acid is incorporated into each product. You will then need to examine the table of amino acid side chains, to determine the properties of each peptide). The top strand is the original sequence for the RNA. The changed RNA CODON is underlined, for each mutation. GCA-UUC-GAA-CUA-AAG-AUG-UAC-AGC GCA-UUC-GAA-CUC-AAG-AUG-UAC-AGC GCA-UUC-GAA-AUC-AAG-AUG-UAC-AGC GCA-UUC-GUA-CUA-AAG-AUG-UAC-AGC GCA-UUC-GAA-CUA-UAG-AUG-UAC-AGC AUAUGCUACAGCGCAUAU What protein could this very short sequence of RNA produce? For that you need to review the genetic code: AUA-UGC-UAC-AGC-GCA-UAU Ile - Cys - Tyr - Ser - Ala- Tyr New protein Problems: Frequency of the appearance of recessive traits in offspring (child inherits the recessive gene from both parents). G G G G G Gr G G G G B B B Br B B B B B B These two populations of females and males each have 10% occurrence of a recessive trait. In the following calculations, assume EQUAL PROBABILITY that any female, and any male, will have a child together. In this case, the probability that Gr x Br will have a child, is given by 0.1 x 0.1 = 0.01. Example 1. The occurrence of the recessive trait within a population is 0.2. -what it the likelihood of a marriage between Gr and Br? -what is the likelihood of a the full recessive in the child? Example 2. The occurrence of the recessive trait within a population is 0.05. -what it the likelihood of a marriage between Gr and Br? -what is the likelihood of a the full recessive in the child? Example 3. The occurrence of the recessive trait within a population is 0.01. -what it the likelihood of a marriage between Gr and Br? -what is the likelihood of a the full recessive in the child? THE NEXT PROBLEMS CONCERN SITUATIONS WHERE MARRIAGE OCCURS BETWEEN POPULATIONS WITH DIFFERENT FREQUENCIES OF THE RECESSIVE TRAIT THAT WE ARE CONSIDERING G G Gr G G G G G G G G G G G G G G G G G G G G G G B B B Br Br B B B B Br B B Br B B B B B Br B B B B B B In this case, the probability that Gr x Br will have a child, is given by 0.04 x 0.2 = 0.008. MARRIAGES BETWEEN FEMALES AND MALES BETWEEN TWO POPULATIONS, WHERE FREQUENCY OF SHARED RECESSIVE TRAITS IS VERY DIFFERENT BETWEEN THE POPULATIONS. Example 4. The occurrence of the recessive trait within POPULATION A is 0.2 AND POPULATION B IS 0.01. -what it the likelihood of a marriage between Gr and Br? -what is the likelihood of a the full recessive in the child? Example 5. The occurrence of the recessive trait within POPULATION A is 0.5 AND POPULATION B IS 0.001. -what it the likelihood of a marriage between Gr and Br? -what is the likelihood of a the full recessive in the child?