Question

what happens to the reading frame during a frameshift mutation? a. it eliminates the gene entirely b. it remains unchanged. c. it is altered, potentially changing the entire protein sequence d. it only affects the first codon which syndrome is caused by a deletion in a small segment of chromosome 22? a. digeorge syndrome b. huntingtons disease c. down syndrome d. cystic fibrosis what type of mutation does not result in any observable change in the organisms phenotype? a. silent mutation b. deletion mutation c. point mutation d. frameshift mutation

Explanation:

1. For the first question: A frameshift mutation occurs due to insertions or deletions of nucleotides not in multiples of three. This shifts the reading - frame of the genetic code, potentially changing the entire protein sequence downstream of the mutation site.
2. For the second question: DiGeorge syndrome is caused by a deletion in a small segment of chromosome 22. Huntington's disease is caused by a trinucleotide repeat expansion, Down syndrome is due to an extra copy of chromosome 21, and Cystic fibrosis is caused by mutations in the CFTR gene.
3. For the third question: A silent mutation is a type of point - mutation that changes a single nucleotide but does not result in a change in the amino - acid sequence of the protein, and thus does not cause any observable change in the organism's phenotype. Deletion, point, and frameshift mutations can often lead to phenotypic changes.

Answer:

1. c. It is altered, potentially changing the entire protein sequence
2. a. DiGeorge syndrome
3. a. Silent mutation