A mutation that involves one or a few nucleotides is called
a) mutagen
b) inversion
c) point mutation
d) translocation
Answer:
c) point mutation
Explanation:
When only one or a few nucleotides of a gene are changed by mutation, this is called a point mutation. A point mutation can add one additional nucleotide to the wild type gene or may delete or substitute a nucleotide from it. For example, if a wild type gene sequence is "ATATATATA", then the addition of "C" at the position 4 will change it into "ATACTATATA". This addition of new nucleotide is called point mutation since only one nucleotide is added to the gene. Point mutations can cause serious genetic disorders such as sickle cell anemia.
The question is incomplete. The complete question is as follows:
Which of the following mutations is most likely to cause a phenotypic change?
A) a duplication of all or most introns
B) a large inversion whose ends are each in intergenic regions
C) a nucleotide substitution in an exon coding for a transmembrane domain
D) a single nucleotide deletion in an exon coding for an active site
E) a frameshift mutation one codon away from the 3' end of the nontemplate strand
Answer: D) a single nucleotide deletion in an exon coding for an active site
Explanation:
Deletion or insertion of a single nucleotide in an axon coding for an active site is called frameshift mutation.
The sequence of codons is read during translation, in order to synthesize a amino acids chain and form a protein from the nucleotide sequence. Frameshift mutations occur when the usual codon sequence is broken by the deletion or addition of one or more nucleotides. For example, if only one nucleotide is removed from the axon sequence during the RNA splicing process, then there will be a disrupted reading frame for all codons before and after the mutation. This may result in several incorrect amino acids being introduced into the protein. Disruption in protein sequence will cause phenotypic change.
Hence, the correct option is D) a single nucleotide deletion in an exon coding for an active site
.
Answer:
Charles Darwin went to the Galapagos Island(s).
Explanation:
Charles Darwin took a boat to the Galapagos Island(s) to study plants and animals that proved to show some similarity between each other, such as two finches, which is actually one of his most popular discoveries.