Question

a cell with mutated dna may not be able to produce proteins accurately. which situations can lead to muta
the dna?
□ mistakes in mrna transcription
□ exposure to x - ray radiation
□ chemicals in some pesticides
□ excess pyruvate from glycolysis
□ uncorrected dna replication errors

Explanation:

• Exposure to X - ray radiation: X - rays are ionizing radiation. Ionizing radiation can break the sugar - phosphate backbone of DNA, cause base damage (such as base deamination, base loss), and lead to DNA mutations.
• Chemicals in some pesticides: Some pesticides contain mutagenic chemicals. For example, some alkylating agents in pesticides can add alkyl groups to DNA bases. This can change the base - pairing properties of the bases. For instance, alkylation of guanine can lead to mis - pairing during DNA replication, resulting in mutations.
• Uncorrected DNA replication errors: DNA polymerase has a proof - reading function, but sometimes it can still make errors during DNA replication. If these errors (such as incorrect base insertion) are not corrected by DNA repair mechanisms (like mismatch repair), they can become permanent mutations in the DNA sequence.
• Mistakes in mRNA transcription: mRNA transcription errors do not change the DNA sequence. The DNA is the template for mRNA synthesis. If there is an error in mRNA transcription, it will affect the protein synthesized from that mRNA molecule, but it will not mutate the DNA itself.
• Excess pyruvate from glycolysis: Pyruvate is a normal intermediate in cellular metabolism (glycolysis). Excess pyruvate (for example, in anaerobic conditions in some cells) is usually metabolized further (such as in fermentation pathways in some organisms). It does not have a direct mutagenic effect on DNA.

Answer:

B. exposure to X - ray radiation, C. chemicals in some pesticides, E. uncorrected DNA replication errors