Genetics - Biology

• DNA: a polymer of nucleotides that carry genetic information in the form of genes
• DNA stands for deoxyribonucleic acid
• Genetics: The study of heredity and variation in organisms.
• Heredity: the passing of traits (genes) from parents to offspring
• Alleles: different forms of a gene
• Gregor Mendel: Father of Genetics
• Chromosome: A threadlike structure of DNA that carries genetic information.
• Locus: The position of a gene on a chromosome.
• Sexual reproduction is the process of combining the genetic information of two parents to produce offspring (Ex. Meiosis)
• Asexual reproduction: Reproduction in which the offspring are genetically identical to the parent (Ex. Mitosis)
• Allele: matching genes 1 from mom, 1 from dad that determine a specific trait (characteristic) for offspring
• Homozygous: Having two identical alleles of a particular gene. (HH or hh)
• Heterozygous: Having two different alleles for a particular gene (Hh)
• Genotype: the coding for a specific trait (Hh, hh, HH)
• Phenotype: how the trait is expressed (the shown characteristic ex. brown hair if H represents hair)
• Dominant alleles: Alleles that are expressed in the phenotype even when the recessive allele is present (Ex. brown hair H is dominant to blonde h, blonde will only show when no brown (H) allele is present)
• Incomplete dominance: both alleles are dominant so both is expressed in a blend
• Co-dominance: both alleles are dominant so both are expressed fully but co-exist (Ex. red & white alleles for hair produce both red and white hairs)
• Multiple alleles: code for blood types

  • A blood: IA IA or IA i
  • B blood: IB IB or IB i
  • AB blood: IB IA
  • O blood: i i
• Genomics: The study of the entire genome of an organism, including the entire set of genes in an organism.
• Tools of genetic engineering:

  • plasmids: allow the passing of DNA through bacteria into now cells via, horizontal gene transfer or transformation
  • restrictive enzymes: allow to cut DNA at specific cites