Biology

• What is a gene mutation?

  A change in the DNA base sequence

  
• Why do mutations occur continuously?

  They are a natural part of DNA processes
• How do mutations affect polypeptides?

  They can lead to changes in amino acid sequences

  
• Why do most mutations not alter polypeptides significantly?

  Because the genetic code is degenerate
• What are the types of mutations in DNA base sequences?

  • Deletion of nucleotides
  • Insertion of nucleotides
  • Substitution of nucleotides
• What is a deletion mutation?

  A nucleotide is randomly deleted from DNA
• What is a frameshift mutation?

  A mutation that alters the reading frame
• How does a deletion mutation affect amino acids?

  It changes the amino acid coded for

  
• What is a substitution mutation?

  A base is swapped for a different base

  
• How does a substitution mutation differ from deletion or insertion?

  It does not have a knock-on effect
• What are the three forms of substitution mutations?

  • Silent mutations
  • Missense mutations
  • Nonsense mutations
• What is a silent mutation?

  It does not alter the amino acid sequence

  
• What is a missense mutation?

  It alters a single amino acid in the chain

  
• What is a nonsense mutation?

  It creates a premature stop codon
• How can a mutation affect protein function?

  By changing the shape of the active site
• What are mutagenic agents?

  Environmental factors that increase mutation rates
• What are examples of mutagenic agents?

  • UV light
  • X-rays
  • Toxic chemicals
• What is the role of proofreading in DNA replication?

  To ensure accuracy and repair damaged DNA
• What is the outcome of mitosis?

  Two genetically identical daughter cells

  
• What is the outcome of meiosis?

  Four genetically different gametes

  
• What is the ploidy of daughter cells in mitosis?

  2n
• What is the ploidy of daughter cells in meiosis?


  n
• Are daughter cells in mitosis genetically identical?

  Yes, they are genetically identical
• Are daughter cells in meiosis genetically identical?

  No, they are genetically different
• What is the significance of genetic variation from meiosis?

  It contributes to genetic diversity in populations
• How does random fertilization increase genetic variation?

  Any male gamete can fuse with any female gamete

  
• What is the role of crossing over in meiosis?

  It creates genetic variation between gametes

  
• What happens during fertilization?

  A male and female gamete fuse to form a zygote

  
• What is the significance of genetically diverse zygotes?

  They contribute to the genetic diversity of a species
• What indicates that meiosis has occurred in a life cycle?

  A reduction division that halves chromosome number

  
• What occurs during metaphase I of meiosis?

  Homologous pairs line up along the equator

  
• What occurs during anaphase I of meiosis?

  Whole chromosomes are pulled to opposite poles

  
• What occurs during telophase I of meiosis?

  Nuclei membranes form around condensed chromosomes

  
• What occurs during cytokinesis of meiosis?

  Cytoplasm divides to form two cells

  
• What is visible during prophase II of meiosis?

  Single whole chromosomes are visible

  
• What occurs during metaphase II of meiosis?

  Single chromosomes line up along the equator

  
• What occurs during anaphase II of meiosis?

  Centromeres divide and chromatids are pulled apart

  
• What occurs during telophase II of meiosis?

  Nuclei form around four groups of chromosomes

  
• What occurs during cytokinesis of meiosis II?

  Four haploid cells are forming

  
• What is the importance of calibration in microscopy?

  To ensure accurate measurements of specimens