BÀi 4: ĐỘt BiẾn Gen - ĐỀ 2

The correct answer is "Đảo vị trí các cặp nuclêôtit." This is because rearranging the nucleotide pairs does not change the number of nucleotides in the gene. The other options, such as adding or losing a pair of nucleotides, would result in a change in the number of nucleotides in the gene.

The frameshift mutation causes the most serious consequences for the polypeptide chain. Frameshift mutations occur when nucleotides are added or deleted from the DNA sequence, causing a shift in the reading frame of the genetic code. This leads to a completely different sequence of amino acids being produced during translation, resulting in a non-functional or truncated protein. In contrast, the other types of mutations listed (missense, synonymous, and inversion) may still result in a functional protein, although they may affect its structure or function to a lesser extent.

After a mutation, the gene remains the same length but gains an additional hydrogen bond. This indicates that there has been a substitution of a base pair. In this case, the mutation involves replacing an A - T base pair with a G - X base pair.

The correct answer is "Thay thế 1 cặp nuclêôtit ở bộ 3 mã hóa axit amin thứ 150." This answer suggests that the mutation in the gene responsible for the protein is caused by the substitution of one nucleotide pair in the codon for the 150th amino acid. This substitution leads to a change in the amino acid sequence and therefore alters the structure and function of the protein.

When a mutation occurs and one nucleotide pair is lost, the number of hydrogen bonds in the gene can decrease by either 2 or 3.

The correct answer is "mất 3 cặp nuclêôtit nằm trong ba bộ ba mã hoá kế tiếp nhau." This means that in the red-eye phenotype, there is a loss of 3 nucleotide pairs in three consecutive codons. This loss of nucleotides results in the production of a protein with a white-eye phenotype, as it is missing one amino acid and has two new amino acids.

When a pair of nucleotides is replaced in the structure of a gene, it can lead to different types of mutations. A frameshift mutation occurs when nucleotides are inserted or deleted in a gene sequence, causing a shift in the reading frame. This can result in a completely different amino acid sequence being produced during protein synthesis, leading to significant changes in the structure and function of the protein. Therefore, a frameshift mutation can have significant consequences.

Dạng đột biến gen này làm mất 1 cặp nuclêôtit ở bộ mã liền sau mã mở đầu, do đó nó sẽ làm biến đổi cấu trúc của phân tử protein tương ứng nhiều nhất.

If the nucleotide G-X is replaced by A-T, it will result in a change in the codon sequence. This change in the codon sequence will lead to a substitution of the amino acid at the 10th position in the polypeptide chain. As a result, the polypeptide chain synthesized will be shorter than normal. Additionally, the amino acid belonging to the 4th triplet can also be altered due to this mutation.

During the process of mitosis, genetic mutations that occur in somatic cells do not get passed on to offspring during asexual reproduction. This is because asexual reproduction involves the production of genetically identical offspring through mitosis, where the parent cell divides into two identical daughter cells. Therefore, any genetic mutations that arise during the process of mitosis in somatic cells will not be transmitted to the offspring during asexual reproduction.