Which of these causes sickle-cell anemia?(1 point)
too many chromosomes
too few chromosomes
base pair deletion
base pair substitution**
If this is wrong can you please explain why...thanks
Base pair substitution is indeed the correct answer for the cause of sickle-cell anemia. Sickle-cell anemia is a genetic disorder caused by a specific type of mutation in the gene responsible for the production of hemoglobin. This mutation involves a single base pair substitution, where one nucleotide is replaced by another in the DNA sequence. In sickle-cell anemia, the amino acid valine is substituted for the normal amino acid glutamic acid in the beta chain of hemoglobin, leading to the production of abnormal hemoglobin molecules that cause the red blood cells to become rigid and sickle-shaped. This substitution is caused by a change in a single nucleotide in the DNA sequence.
The correct answer is base pair substitution. Sickle-cell anemia is a genetic disorder caused by a specific mutation in the hemoglobin gene that affects the structure and function of red blood cells. This mutation involves a base pair substitution, specifically a change of one nucleotide (base) in the DNA sequence.
To understand why base pair substitution causes sickle-cell anemia, let's briefly explain how genes work. Genes are segments of DNA that contain instructions for producing proteins, which are essential for the body's functions. Each gene is made up of a specific sequence of nucleotides, and the order of these nucleotides determines the order of amino acids in a protein.
In the case of sickle-cell anemia, the mutation affects the gene responsible for producing hemoglobin, a protein that carries oxygen in red blood cells. The specific base pair substitution in this gene results in a change of one amino acid in the hemoglobin protein. This altered amino acid causes the red blood cells to become deformed and form a sickle shape, impairing their ability to carry oxygen efficiently.
Now, let's address the other options and explain why they are incorrect:
- Too many chromosomes or too few chromosomes are conditions called aneuploidy, where an individual has an abnormal number of chromosomes. Sickle-cell anemia is not caused by aneuploidy, but rather by a specific genetic mutation.
- Base pair deletion refers to the removal of one or more nucleotides from a DNA sequence. While deletions in DNA can cause various genetic disorders, sickle-cell anemia is specifically caused by the base pair substitution mutation mentioned earlier.
In conclusion, the correct cause of sickle-cell anemia is base pair substitution, as it results in a specific mutation in the hemoglobin gene that affects the structure and function of red blood cells.