The shrunken gene of wheat encodes a large enzyme that converts glucose to starch in its grains.
How would insertion of a 1 kb transposon into codon 23 of this gene affect the protein produced from
this allele?
A. The protein would be longer and still functional.
B. The protein would be much shorter and nonfunctional.
C. The shrunken protein would function as a transposase.
D. The gene would not be transcribed or translated.
E. More protein would be made.
The insertion of a 1 kb transposon into codon 23 of the shrunken gene of wheat would likely result in a frameshift mutation. This means that the reading frame of the gene would be disrupted, causing a change in the sequence of amino acids that make up the protein.
Based on this information, we can eliminate options A ("The protein would be longer and still functional") and E ("More protein would be made") since the transposon insertion would likely result in a nonfunctional or altered protein rather than a longer or increased amount of protein.
Option C ("The shrunken protein would function as a transposase") is also not correct. The shrunken protein is known to convert glucose to starch in grains, rather than functioning as a transposase enzyme.
Therefore, the most likely answer is B. "The protein would be much shorter and nonfunctional" as the frameshift mutation caused by the transposon insertion would disrupt the normal protein structure and likely render it nonfunctional.
To understand the effect of inserting a 1 kb transposon into codon 23 of the shrunken gene, we need to consider the consequences of this modification on the resulting protein.
The insertion of a transposon into the gene sequence can disrupt the normal reading frame, leading to a change in the amino acid sequence produced during translation. Depending on the specific location and nature of the transposon insertion, it can result in various outcomes.
In this case, if the transposon inserts into codon 23 of the gene, it is likely to cause a frameshift mutation. This means that the reading frame of the gene will be shifted, altering the triplet codon sequence and thus changing the amino acid sequence of the protein.
Given that a frameshift mutation occurs, the prediction is that the resulting protein would be shorter and likely nonfunctional. The reason is that after the insertion, the entire protein sequence downstream of the mutation would be affected, leading to a significant disruption in the protein's structure and function.
Therefore, the correct answer to the question is B. The protein would be much shorter and nonfunctional.
It's essential to note that this explanation assumes a typical scenario based on the information provided. Real-life genetic modifications may vary, and further analysis and experimentation would be required to confirm the exact impact of this specific transposon insertion on the shrunken gene and its protein.