DNA and inheritance

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Created by
Jorja Serwata

Cards (12)

  • DNA structure

    Two long chains of alternating sugar and phosphate
  • DNA bases

    • Guanine (G) only pairs with Cytosine (C)
    • Adenine (A) only pairs with Thymine (T)
  • DNA triplet code

    1. 3 bases form a triplet code
    2. Triplet of bases codes for a particular amino acid
    3. Chains of amino acids form proteins
  • DNA is a code
  • DNA is constructed from 2 long chains of alternating sugar and phosphate
  • Genes

    • Code for characteristics
    • Can have different versions called alleles
  • Alleles are inherited through sexual reproduction, one from each parent so they occur in pairs
  • Genetic profiling

    • DNA sample is cut into short pieces which are then separated into bands
    • Can be used in criminal cases, paternity cases, and comparing species for classification purposes
    • Can identify genes associated with disease
    • Raises ethical concerns
  • Genetic modification

    • Allows genetic material from one organism to be transferred into the DNA of another organism
    • Advantages: Genes for disease resistance can be transferred to crop plants to increase yield, Herbicide resistant genes can also increase yield as herbicides can be used to kill competing plants (weeds)
    • Disadvantages: Creation of super weeds if the herbicide resistance genes are taken up by weed species, Unknown long-term effects of modifying genomes, Unknown health effects of eating modified organisms
  • Alleles

    Dominant allele is represented by a capital letter, recessive allele is represented by a lowercase letter
  • Punnett square

    1. Shows the possible genotypes and phenotypes of offspring from a genetic cross
    2. Heterozygous parents have 2 different alleles of the same gene
    3. Offspring show a 3:1 ratio of dominant to recessive traits, and a 1:2:1 ratio of homozygous dominant to heterozygous to homozygous recessive genotypes
  • Sex determination

    • In humans, sex is determined by chromosome pair 23, with XX for females and XY for males
    • Each fertilisation has a 50% chance of producing a male or female offspring