AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

GENE MUTATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
When a substitution occurs and there is a change to one amino acid in the sequence it is called ____
A
missense
B
nonsense
C
silent
D
exciting
Explanation: 

Detailed explanation-1: -Missense: A missense variant is a type of substitution in which the nucleotide change results in the replacement of one protein building block (amino acid) with another in the protein made from the gene. The amino acid change may alter the function of the protein.

Detailed explanation-2: -(MIS-sens myoo-TAY-shun) A genetic alteration in which a single base pair substitution alters the genetic code in a way that produces an amino acid that is different from the usual amino acid at that position. Some missense variants (or mutations) will alter the function of the protein. Also called missense variant.

Detailed explanation-3: -Frame-shift mutations occur when a base is added or removed from the sequence. Non-sense mutations create a stop codon, which can prevent the protein from being produced entirely, while missense mutations result in the substitution of one amino acid for another.

Detailed explanation-4: -Listen to pronunciation. (MIS-sens myoo-TAY-shun) A change in the DNA sequence of a gene that results in one amino acid (protein building block) being replaced with an amino acid that is different from the usual one at that position in the gene.

Detailed explanation-5: -Missense codons (missense mutations): A change in a single amino acid that results from a point mutation in the DNA sequence. Nonsense codons (nonsense mutations): The conversion of a codon from one that encodes an amino acid to one that acts as a stop codon due to a point mutation in the DNA sequence.

There is 1 question to complete.