Which of the following statements about mutations are true? * Mutations are changes in the nucleotide sequence of a DNA molecule. Mutations are changes in the phosphate backbone of DNA which always have han effects. Mutations code for that gene. may cause a change in the protein sequence resulting from the genetic Mutations can be harmful, neutral, or beneficial to the organism. Mutations decrease the genetic diversity of organisms
The Correct Answer and Explanation is :
The correct statements are:
- Mutations are changes in the nucleotide sequence of a DNA molecule.
- Mutations can be harmful, neutral, or beneficial to the organism.
Explanation:
- Mutations are changes in the nucleotide sequence of a DNA molecule:
This is the definition of a mutation. Mutations occur when there is a change in the sequence of nucleotides (A, T, C, G) in the DNA, which can happen due to various factors such as errors during DNA replication, environmental factors (e.g., radiation), or chemical exposure. These changes may result in altered genes and affect cellular functions. - Mutations can be harmful, neutral, or beneficial to the organism:
Mutations can have varying effects on the organism depending on the nature and location of the mutation.
- Harmful mutations can lead to diseases or dysfunctional proteins (e.g., cystic fibrosis due to a mutation in the CFTR gene).
- Neutral mutations do not affect the organism’s fitness or function and might go unnoticed. They may occur in non-coding regions of DNA or result in silent mutations, where the change in DNA does not affect the resulting protein.
- Beneficial mutations can provide an advantage to the organism in a particular environment, such as mutations that provide resistance to diseases or allow for better adaptation to environmental changes.
The incorrect statements:
- Mutations are changes in the phosphate backbone of DNA which always have effects: This is not accurate. Mutations generally occur in the nucleotide sequence and may or may not affect the structure of the phosphate backbone. Additionally, mutations do not always have noticeable effects. Silent mutations, for example, can change the nucleotide sequence without altering the protein product.
- Mutations code for that gene: This statement is misleading. Mutations themselves do not “code for” a gene; rather, they alter the gene’s sequence. A mutation can affect the gene’s expression or the protein it codes for, but mutations do not code for a gene.
- Mutations decrease the genetic diversity of organisms: This is incorrect. Mutations are a major source of genetic diversity, as they introduce new variations into the gene pool. While some mutations may reduce an organism’s fitness, the overall effect of mutations increases genetic diversity in populations over time.