Question

2a. The enzyme called Pheide a Oxygenase (PAO) catalyses the degradation of chlorophyll. Mendel’s I gene (yellow peas) codes for this enzyme. If this gene is mutated, what will happen to the pea colour? 2b. What was discovered when looking at the PAO levels between heterozygous and homozygous plants? 2c. Gibberellin is a plant hormone that promotes the elongation of plant stems. It is produced in a series of reactions requiring an enzyme coded for by a specific gene. If this gene is isolated, and mutated, how will this affect the height of the plant?

Answer 1

The answers for the alternatives are:

a) The PAO enzyme catalyses the degradation of chlorophyl, when the gene for the production of PAO is mutated, the pea plant won't have a functional PAO, being the chlorophyl in that plant not degradated, in consequence the pea plants will remain green and not turn out yellow like their gene stipule by Mendel's Law.

b) When made the comparison between heterozygous and homozygous for PAO enzyme in plants, it was discovered that heterozygous will have half as much PAO as a homozygous dominant for the PAO gene, since the lower enzyme level is enough to produce PAO for the plant degradate chlorophyl.

c) If the gene for the enzyme related to promote elogation of plant stems is mutated, it is expected that the height of the plant will be lower than with the specific gene working, because the reactions and gibberellin production and distribution are directed affect by that genetic modification.