Size of Mutations and Chromosomal Abnormalities

Vocabulary flashcards covering the sizes and types of DNA mutations, ranging from single-nucleotide point mutations and lesions to large-scale chromosomal abnormalities and aneuploidy.

Nucleotide

The basic unit characterized as the 'letters of information' in DNA.

Point mutation

A mutation in which one nucleotide or letter of information is changed in DNA.

Dimerization

A DNA lesion caused by physical carcinogens in which two letters or nucleotides on the same strand fuse together and bend the DNA.

Single-strand break

A physical break in DNA caused by physical or chemical carcinogens where multiple nucleotides are destroyed on one strand.

Double-strand break

A physical break where multiple nucleotides are destroyed on both strands, splitting the DNA into $2$ separate pieces.

Insertion

A mutation during DNA synthesis where one or more letters are added to the DNA sequence.

Deletion

A mutation occurring during DNA synthesis or meiosis where one or more letters are removed from the DNA.

Substitution

A mutation where one letter or nucleotide in the DNA sequence is replaced with another one (such as $C \rightarrow A$).

DNA repair in normal cells vs. cancer cells

Normal cells proofread and correct DNA (repairing, removing, and replacing damaged or fused letters so information stays the same), while cancer cells remain changed or attempt repair by adding the wrong information.

Karyotype

A diagram that shows each DNA molecule or chromosome, typically showing $46$ chromosomes in a normal human cell.

Chromosome abnormality

A large-scale mutation involving $100\text{s} - 1000\text{s}$ of letters where pieces of different chromosomes fuse together, resulting from errors in mitosis, meiosis, or exposure to carcinogens.

Aneuploidy

An abnormal number of chromosomes in a cell, often arising from errors during mitosis.