17. When errors in nucleotide sequencing occur,
a. DNA polymerases replaces the incorrect nucleotide with the correct nucleotide
b. enzymes dissolve the incorrect nucleotide so DNA polymerase can add the correct one
c. purines replace pyrimidines in the DNA molecule
d. DNA polymerase proofreads for errors while another enzyme corrects it
I'd love some help with this! I'm kind of leaning towards A. What do you think?
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Choose from the general topics at the right and then find the specifics you need within each topic.
To determine the correct answer, let's break down the options and understand the process of error correction in nucleotide sequencing.
During nucleotide sequencing, errors can occur when incorrect nucleotides are incorporated into the growing DNA strand. These errors can lead to mutations and affect the accuracy of genetic information.
Option a. DNA polymerases replace the incorrect nucleotide with the correct nucleotide: This option is partially correct. DNA polymerases do have the ability to correct errors during nucleotide sequencing. They possess a proofreading function that allows them to recognize and remove incorrectly incorporated nucleotides from the growing DNA chain. The DNA polymerase then replaces the incorrect nucleotide with the correct one.
Option b. Enzymes dissolve the incorrect nucleotide so DNA polymerase can add the correct one: This option is not accurate. Enzymes do not dissolve incorrect nucleotides. However, DNA polymerases can remove the incorrectly incorporated nucleotide themselves.
Option c. Purines replace pyrimidines in the DNA molecule: This option is not accurate. Purines (adenine and guanine) and pyrimidines (cytosine and thymine) are both types of nucleotide bases found in DNA, but errors in sequencing do not involve the replacement of one type with the other.
Option d. DNA polymerase proofreads for errors while another enzyme corrects it: This option is partially correct. As mentioned earlier, DNA polymerases have the ability to proofread and correct errors by removing and replacing incorrect nucleotides. However, the correction is achieved by the same enzyme and not by another separate enzyme.
Therefore, the correct answer is:
d. DNA polymerase proofreads for errors while another enzyme corrects it.
(Explanation: The mistake in option d is that another enzyme does not correct the error. DNA polymerase itself corrects the error.)
In conclusion, while option a contains some correct information, option d provides a more accurate description of the error correction process during nucleotide sequencing. DNA polymerases possess a proofreading activity to identify and correct errors in nucleotide incorporation.