NEET BIOLOGY

THIS IS AN ESSAY QUESTION. IT HAS 3 PARTS. YOU MUST CONSTRUCT YOUR OWN ANSWERS. GOOGLE THE AP CENTRAL WEBSITE TO FIND THE ANSWER. YOUR OWN YOUR OWN ON THIS ONE! I’M NOT PRECHECKING YOUR ANSWERS BEFORE THE TEST EITHER!Gibberellin is the primary plant hormone that promotes stem elongation. GA 3-beta-hydroxylase (GA3H) is the enzyme that catalyzes the reaction that converts a precursor of gibberellin to the active form of gibberellin. A mutation in the GA3H gene results in a short plant phenotype. When a pure-breeding tall plant is crossed with a pure-breeding short plant, all offspring in the F1 generation are tall. When the F1 plants are crossed with each other, 75% of the plants in the F2 are tall and 25% of the plants are short.1) The wild-type allele encodes a GA3H enzyme with alanine (Ala), a nonpolar amino acid, at position 229. The mutant allele encodes a GA3H enzyme with threonine (Thr), a polar amino acid, at position 229. Describe the effect of the mutation on the enzyme and provide reasoning to support how this mutation results in a short plant phenotype in homozygous recessive plants.2) Using a codon chart, predict the change in the codon sequence that resulted in the substitution of alanine for threonine at amino acid position 229.3) Describe how individuals with one (heterozygous) or two (homozygous) copies of the wild-type GA3H allele can have the same phenotype.