Unit III: Genetics vocabulary

• Gregor Mendel (1850s) was an Austrian monk who grew pea plants
• cross pollination happens when the pollen is transferred to a different plant
• self pollination occurs when the anther of a flower is transferred to a stigma on the same plant
• the P generation is the first generation of a genetic cross (the parent)
• true breeding is when self pollinated plants only creates offspring with itself
• filial (F1) is the first generation (son)
• Mendel's conclusion

  1. traits do not blend
  2. each individual holds two traits for each characteristic
• the law of dominance states that some traits (dominant) when present completely mask the traits of others (recessive)
• the law of segregation states that when creating gametes only one of the two traits can be given off
• genotypes are the traits carried by an organism
• phenotype is the trait shown by an organism
• heterozygous is when an individual has two different traits for a characteristic
• homozygous is when an individual carries two of the same trait ( dominant or recessive )
• law of independent assortment : how two traits segregate during meiosis , has no effect on traits of other characteristics
• a dihybrid cross is a genetic cross involving two characteristics
• a monohybrid cross is genetic cross involving a single characteristic
• a punnett square is a method of visualizing possibilities of a genetic cross
• multiple alleles is when there exists more than two possible traits in a population

  ex) eye color: brown , green , and blue
• codominance is when in the heterozygous condition both traits are fully expressed
• incomplete dominance is when in the heterozygous condition a third intermediate phenotype is shown

  ex) heterozygous snapdragon ( red white ) THE PHENOTYPE IS PINK
• a frameshift mutation is any additions or deletions that alter the reading frame so every downstream amino acid will be changed
• a substitution mutation occurs when an amino acid is replaced with another
• a silent mutation is a mutation that does not change the amino acid
• a mutation is an error in DNA copy that could lead to a dysfunctional protein
• rRNA

  • ribosome
  • translation : uses the mRNA info to build the protein
• tRNA

  • transfer
  • responsible for translation along with rRNA
• mRNA

  • messenger
  • transcription : the DNA template is copied by mRNA
• RNA

  • ribonucleic acid
  • single stranded
  • no thymine (T) , replaced with uracil (u)
• protein synthesis is DNA that provides the template for the creation of proteins
• DNA polymerase is a protein that adds new nucleotides to the string

  • can only travel in 5' direction
• antiparallel refers to the fact that the polynucleotide strands of DNA are pointed in opposite directions
• nucleotides are building blocks of DNA

  • Adenine (A)
  • Cytosine (C)
  • Thymine (T)
  • Guanine (G)
  • chargaff's rule : A = T & C = G
• DNA is the molecule of life
• morgan thomas hunt (1950s) is a scientist that worked with fruit flies and discovered sex linked traits

  • concluded that genes are carried in chromosomes
• mutant type (recessive) is any less common trait in a population
• wild type (dominant) is the most common trait in a population
• sex linked traits are traits that are found on sex chromosomes

  • usually on the x chromosome