Mutations

• What can cause chromosome mutations in number?

  Chromosome non-disjunction during meiosis
• What is non-disjunction?

  Unequal splitting of chromosomes during anaphase
• How many forms can non-disjunction occur in?

  Two forms
• What are the two forms of non-disjunction?

  Polyploidy and aneuploidy
• What is polyploidy primarily associated with?

  Plants
• What does polyploidy involve?

  Changes in whole sets of chromosomes
• What happens when organisms have three or more sets of chromosomes?

  They exhibit polyploidy
• What are the possible results of polyploidy?

  Triploid and tetraploid
• What is aneuploidy?

  Changes in the number of individual chromosomes
• What can cause aneuploidy during meiosis?

  Failure of homologous pairs to separate
• What is the result of non-disjunction in gametes?

  One more or one fewer chromosome
• What are the key differences between polyploidy and aneuploidy?

  • Polyploidy: changes in whole sets of chromosomes
  • Aneuploidy: changes in individual chromosomes
  • Polyploidy mainly occurs in plants
  • Aneuploidy results from non-disjunction
• Nit all mutations in the nucleotide sequence of a gene cause a change in the structure of a polypeptide?

  Aminoacids codes for the same triplet codes

  Occurs in introns-non coding sequence
• What are gene mutations?

  Gene mutations involve a change in the base sequence of chromosomes
• What are the two main types of gene mutations?

  Gene mutations can arise from insertion and base substitution
• What can increase the rate of gene mutations?

  Mutagens can increase the rate of gene mutations
• How do gene mutations alter the encoded polypeptide?

  Mutations alter the gene, resulting in a different amino acid sequence
• How does a change in the amino acid sequence affect the protein structure?

  The altered amino acid sequence changes the tertiary structure of the protein
• How can changes to a gene result in cancer?

  Mutations to a gene can alter its function and lead to cancer
• How can ultraviolet light and high-energy particles cause DNA damage?

  Ultraviolet light and high-energy particles can disrupt the structure of DNA
• What is the term for chemicals that can alter the structure of DNA?

  Carcinogens are chemicals that can alter the structure of DNA
• What are the key differences between gene mutations and chromosomal mutations?

  • Gene mutations involve changes in the base sequence of a gene
  • Chromosomal mutations involve changes in the structure or number of chromosomes
  • Gene mutations can alter the amino acid sequence and structure of a protein
  • Chromosomal mutations can affect the expression and function of multiple genes
• How can gene mutations lead to cancer?

  • Mutations can alter the function of genes involved in cell growth and division
  • This can lead to uncontrolled cell proliferation and the development of cancer
  • Common mutations in cancer include those in tumor suppressor genes and oncogenes
• What are the differences between ionizing and non-ionizing radiation as mutagenic agents?

  • Ionizing radiation (e.g. gamma rays, X-rays) has enough energy to directly damage DNA
  • Non-ionizing radiation (e.g. UV light) can indirectly damage DNA by creating reactive molecules
  • Ionizing radiation is generally more potent as a mutagen than non-ionizing radiation
  • Both types of radiation can lead to gene mutations and chromosomal abnormalities
• What are the key differences between carcinogens and mutagens?

  • Carcinogens are chemicals that can alter the structure of DNA and interfere with transcription
  • Mutagens are agents that can increase the rate of gene mutations
  • Carcinogens can lead to cancer by causing permanent changes in DNA
  • Mutagens can cause a variety of genetic changes, some of which may lead to cancer