Question

during the production of a gamete, a guanine replaces a thymine in a growing strand of dna. the dna repair mechanisms do not catch the mistake, and the resulting offspring has a mutation. which claim is best supported by this information? a. inheritable genetic variations can be caused by errors during dna replication. b. mutations caused by environmental factors can result in inheritable genetic variations. c. new allele combinations that occur during lateral gene transfer can cause inheritable genetic variations. d. inheritable genetic variations can occur during meiosis due to independent assortment.

Explanation:

The problem describes a situation where an error during DNA replication (guanine replacing thymine) occurs in a gamete - producing cell, and the offspring has a mutation.

• Option A: This situation directly shows that an error during DNA replication (in a gamete - forming cell) leads to an inheritable mutation (as it is in a gamete, which can pass the genetic change to offspring).
• Option B: There is no mention of environmental factors causing the mutation in the given information.
• Option C: Lateral gene transfer is not relevant to the described scenario of DNA replication error in gamete production.
• Option D: Independent assortment during meiosis is about the distribution of chromosomes, not about a single - base substitution during DNA replication as described.

Answer:

A. Inheritable genetic variations can be caused by errors during DNA replication.