Point Mutations and Protein Function Quiz

Point Mutations

• Missense mutation results in the substitution of one amino acid for another in the coded protein.
• Nonsense mutation leads to a stop codon and results in a truncated protein with limited or no function.
• Silent mutation results in the substitution of a base that encodes the same amino acid.

Gene Processing

• The intron region of the gene is responsible for posttranslational processing and defective splicing.

Inheritance Patterns

Autosomal Dominant

• Characterized by affected offspring usually having one affected parent and an equal number of males and females affected.

Autosomal Recessive

• Characterized by parents of affected individuals being heterozygotes, with an equal number of males and females affected.

X-Linked Dominant

• Characterized by transmission from either parent being vertical, with a sex ratio of twice as many affected females as males.

X-Linked Recessive

• Characterized by transmission from either parent being vertical, with a sex ratio of more affected males than females.

Y-Linked

• Characterized by transmission only from father to son and all males being affected.

Mitochondrial Inheritance

• Characterized by mtDNA being subject to mutation and inherited maternally.

X-Linked Recessive (Female Parent)

• Affected female parents having 50% affected sons and 50% affected daughters, and 50% daughters unaffected; and 50% sons unaffected.

X-Linked Dominant (Male Parent)

• Affected male parents having all sons unaffected and all daughters carriers.

X-Linked Dominant (Female Parent)

• Affected female parents having 50% affected daughters and 50% non-carrier daughters.

Mitochondrial Inheritance (Female Parent)

• Daughters affected and sons unaffected.

Test your knowledge on point mutations and their effects on protein function with this quiz. Learn about missense mutations, conservative and nonconservative substitutions, as well as nonsense mutations and their impact on protein structure and function.