genetic variation

• What is the genetic makeup of an organism called?

  Genotype
• How is genotype symbolised?

  With letters
• What does the term "heterozygous" mean?

  Having two different alleles for a trait
• What does the term "homozygous" mean?

  Having two identical alleles for a trait
• What is the physical appearance of an organism called?

  Phenotype
• What factors can influence the phenotype of an organism?

  Environment
• What is the correspondence between nucleic acid bases and amino acids called?

  Genetic code
• How is the genetic code read?

  In triplicate (codon)
• How many amino acids are encoded by 4 nucleotides?

  20
• Why is the genetic code considered degenerate?

  Multiple codons can code for the same amino acid

  
• How many amino acids can humans produce?

  10
• What determines protein folding and stability?

  Amino acid charge, size, shape, reactivity, hydrophobicity
• What is the origin of all genetic variation?

  Mutation
• What is a gene mutation?

  A change in a single base pair

  
• What is a chromosome mutation?

  A visible change in chromosome structure
• What are polymorphisms?

  Common genetic variations in populations
• What is a spontaneous mutation?

  A mutation with no known cause
• What is an induced mutation?

  A mutation caused by external factors
• What is a somatic mutation?

  A mutation in body cells, not passed to offspring
• What is a gamete mutation?

  A mutation in germ cells, passed to offspring
• What is a point mutation?

  A change in a single base pair
• What is a frameshift mutation?

  A mutation that alters the reading frame of the gene

  
• What is a silent mutation?

  A mutation that does not change the amino acid sequence

  
• What is a missense mutation?

  A mutation that changes one amino acid to another

  
• What is a nonsense mutation?

  A mutation that introduces a stop codon

  
• What are purine bases?

  Adenine and guanine
• What are pyrimidine bases?

  Thymine, cytosine, and uracil
• What is a transition mutation?

  A purine substituted for a purine or a pyrimidine for a pyrimidine

  
• What is a transversion mutation?

  A purine substituted for a pyrimidine or vice versa

  
• What disease is caused by a missense mutation?

  Sickle cell anemia

  
• What disease is caused by a deletion mutation?

  Cystic fibrosis
• What disease is caused by a trinucleotide repeat expansion?

  Huntington's disease
• What is an indel mutation?

  Insertion or deletion of nucleotides

  
• What is an in-frame deletion or insertion?

  Deletion or insertion of a multiple of 3 nucleotides

  
• What is a splice site mutation?

  A mutation at the intron-exon boundary
• What is a gain-of-function mutation?

  A mutation that results in a new or enhanced function
• What is a loss-of-function mutation?

  A mutation that results in reduced or absent function
• What is haploinsufficiency?

  Loss of function due to 50% of gene product
• What is a dominant negative mutation?

  Abnormal protein interferes with normal protein function
• What are the types of point mutations?

  • Substitution
  • Deletion
  • Insertion