Chromosomal Mutations Quiz

What is the result of a nonsense mutation?

Which type of mutation involves the addition, deletion, or alteration of a single nucleotide base?

What is the impact of a missense mutation on the genetic code?

Which mutation type involves changes in the number or structure of chromosomes?

In which type of mutation does only a single gene get affected during DNA replication?

What causes a conservative mutation?

Which mutation type results in a genetic alteration where one single base pair is altered?

What is the characteristic feature of an inversion mutation?

Which type of mutation involves the repetition of a segment of genetic material?

What effect does a deletion mutation have on the DNA sequence?

Chromosomal Mutations

Inversion: a segment of a chromosome is removed and then replaced within the chromosome in reverse order, e.g., Hemophilia A, where an inversion mutation inhibits the ability to blood clot.
Insertion: a larger segment of a chromosome is inserted into a smaller segment, e.g., Fragile X Syndrome, where CGG nucleotides are inserted over 200 times in the DNA segment, causing learning disabilities and social and behavior problems.

Translocation

A part of a chromosome breaks off and relocates to a completely different chromosome, e.g., Trisomy 21, which causes Down syndrome, a condition characterized by a mildly-to-moderately low IQ, delayed speech, and distinct physical features such as a flattened face and almond-shaped eyes.

Point Mutations

Silent mutation: an alteration in a nitrogenous base that produces the same amino acid.
Frameshift mutation: a disruption in the normal sequence of codons due to the insertion or deletion of one or more nitrogenous bases, e.g., Cystic fibrosis, a recessive disease caused by mutations in the CFTR gene, leading to a buildup of thick mucus and complications in various organs.

Chromosomes and Genes

Chromosomes are threadlike structures made of a DNA molecule and protein.
Humans have 22 pairs of autosomes and 1 pair of sex chromosomes.
Autosomal traits are controlled by the 22 pairs of autosomes and are inherited in the same way regardless of the sex of the parent or offspring.
Sex chromosomes determine the sex of offspring.

Test your knowledge on chromosomal mutations including inversion and insertion mutations. Learn about how changes in chromosome structure can lead to genetic disorders like Hemophilia A and Fragile X Syndrome.