Genetics and Mutations Quiz

Mutations

• Mutations occur due to incorrect pairing of bases during the replication process.
• Mutations can also occur due to external factors, known as mutagens.

Chromosomes

• Chromosomes are thread-like structures composed of protein and a single molecule of DNA.
• They serve to carry genomic information from cell to cell.

Genes

• Genes are the basic physical and functional units of heredity.
• Genes are made up of DNA and act as instructions to make proteins.

Types of Mutations

Chromosomal Mutations

• Affect the structure or number of chromosomes.
• Types of chromosomal mutations: • Deletion: a part of a chromosome is deleted, making it shorter than normal. • Example: William-Beuren Syndrome • Duplication: a part of a chromosome becomes longer due to an extra segment. • Example: Down Syndrome • Translocation: a transfer of genetic material between two non-homologous chromosomes. • Example: Leukemia • Inversion: a part of a chromosome is attached in reverse orientation. • Example: Hemophilia • Nondisjunction: the chromosomes that make up a pair fail to separate, resulting in an unequal number of chromosomes in the cell. • Example: Turner Syndrome

Gene Mutations

• Affect the nucleotide sequence in a gene.
• Types of gene mutations: • Point Mutation: replacement of a nucleotide. • Affects a gamete or sex cell, causing a disorder that can be transmitted to the next generation. • Missense Mutation: substitution in the amino acid of a protein. • Example: Sickle Cell Anemia • Nonsense Mutation: a stop codon is added to prevent the effect of a substitution in protein production. • Example: Duchenne Muscular Dystrophy • Frameshift Mutation: deletion or insertion of one or few nucleotide pairs in DNA. • Example: Cystic Fibrosis