Mutations and Gene Editing

• What are gene mutations?

  Fundamental changes in the DNA sequence that can impact an organism's phenotype
• What are the types of mutations and their consequences?

  • Substitutions: Change one nucleotide for another.
  • Insertions: Add one or more nucleotides, causing frameshift mutations.
  • Deletions: Remove one or more nucleotides, also causing frameshift mutations.
• How does a substitution mutation affect a sentence analogy?

  A substitution changes a single letter, altering meaning slightly but keeping it sensible
• What is a frameshift mutation?

  A mutation that shifts the reading frame of the gene due to insertions or deletions
• What is a single-nucleotide polymorphism (SNP)?

  A variation at a single nucleotide position in the DNA sequence among individuals
• What are the types of outcomes from base substitutions?

  Silent, missense, and nonsense mutations
• What is the impact of silent mutations?

  They do not change the amino acid sequence
• What is the consequence of a missense mutation?

  A different amino acid is produced in the polypeptide chain
• What happens in a nonsense mutation?

  A stop codon is created, leading to a truncated protein
• How do insertions and deletions affect polypeptides?

  They can lead to non-functional proteins due to frameshift mutations
• What are trinucleotide repeats in the HTT gene associated with?

  Huntington's disease due to excessive CAG repeats
• What is the delta 32 mutation in the CCR5 gene associated with?

  Resistance to HIV infection due to a non-functional receptor
• What are mutagens?

  Agents that increase the frequency of mutations in DNA
• What are examples of chemical mutagens?

  Alkylating agents and aromatic hydrocarbons
• How does UV radiation affect DNA?

  It can cause the formation of pyrimidine dimers
• What is the randomness of mutation occurrence?

  Mutations can happen at any point in the DNA sequence, independent of needs
• What is the significance of germ cells in mutations?

  Mutations in germ cells can be passed to the next generation
• What are somatic cells?

  Cells that make up the majority of an organism's body and are not involved in reproduction
• How can somatic mutations lead to cancer?

  They can disrupt normal cell regulation, leading to uncontrolled growth
• What role do mutations play in evolution?

  They serve as the original source of genetic variation within populations
• What is the role of natural selection in relation to mutations?

  Natural selection acts on genetic variation produced by mutations
• What is CRISPR-Cas9?

  A gene editing tool adapted from a natural defense mechanism in bacteria
• What are the components of CRISPR-Cas9?

  Guide RNA (gRNA) and Cas9 enzyme
• What is the process of CRISPR-Cas9 gene editing?

  The gRNA guides Cas9 to the target DNA sequence, where it cuts the DNA
• What are the molecular effects of mutations?

  They can alter protein structure and function at the DNA, RNA, and protein levels
• What is the genetic basis of sickle cell anemia?

  A single base substitution in the β-globin gene leads to altered hemoglobin
• What are the consequences of sickle cell anemia?

  Altered red blood cell shape, leading to blocked blood vessels and anemia
• What is GenBank?

  A comprehensive database containing publicly available nucleotide sequences
• How do researchers use GenBank for genetic comparisons?

  They retrieve and align DNA sequences to identify differences
• What are ethical considerations in gene editing?

  Off-target effects, germline editing, and enhancement vs. treatment debates
• Why is it important to understand the ethical implications of gene editing?

  To grasp both the potential benefits and risks associated with these technologies