Bio 1 Final

• Gregor Mendel conducted crossbreeding experiments with garden peas from 1856-1863
• Allele


  Variant form of a gene
• Genotype


  Genetic makeup (alleles) of an organism
• Phenotype


  Observable traits of an organism determined by genotype
• Punnett Square


  Visual tool to calculate genotypes and phenotypes from crossbreeding
• P generation


  Parental generation
• F1 generation


  First filial generation
• F2 generation


  Second filial generation
• Law of Segregation


  • 2 alleles separate in meiosis and are distributed into gametes in diploid organisms
• Heterozygote


  Organism with two different alleles for a particular gene
• Monohybrid


  Individual heterozygous for a particular gene
• Monohybrid cross


  • Mating of two monohybrids produces a 3:1 phenotypic ratio
• Homozygote

  • Organism with two identical alleles for a particular gene, results in true breeding
• Law of Independent Assortment


  • Alleles for different genes segregate independently during gamete formation
• Dihybrid cross


  Cross between individuals heterozygous for two genes, results in a 9:3:3:1 phenotypic ratio
• Multiplication Rule


  Probability of A and B occurring together is the product of their individual probabilities
• Addition Rule


  Probability of E or F or G occurring is the sum of their individual probabilities
• Multifactorial characters


  Influenced by the combined effects of genes and environment
• Incomplete Dominance


  Mixing of two phenotypes
• Codominance


  Two phenotypes show up at the same time
• Epistasis


  One gene affects the physical expression of another gene
• Polygenic Inheritance


  Many different genes affect the same trait
• Pleiotropy


  One gene affects several phenotypic traits
• Somatic animal cells are diploid, containing the full set of chromosomes
• DNA information is used to make proteins, mRNA, and rRNA
• Primary structure of protein


  Sequence of amino acids
• Secondary structure of protein


  Result of hydrogen bonds in the polypeptide backbone
• Tertiary structure of protein


  Stabilized by side chain interactions, determines the overall 3D structure
• Quaternary structure of protein


  Results when multiple polypeptides associate
• A single amino acid change can alter primary and quaternary protein structure, resulting in abnormal hemoglobin
• Amniocentesis


  Physician inserts needle to remove amniotic fluid to find disorders
• CVS


  Physician removes small tissue sample
• Chromosomal mutations

  Deletion, duplication, inversion, translocation
• Nondisjunction


  Failure to separate homologous chromosomes or sister chromatids in cell division
• Covalent bonds


  Hold adjacent nucleotides together in DNA backbone
• Hydrogen bonds


  Hold complementary bases of opposite DNA strands
• Van der Waals interactions

  Occur between stacked nucleotide units that hold DNA together
• DNA polymerase


  Enzyme that catalyzes addition of nucleotides to the 3' end
• Helicase


  Breaks hydrogen bonds between bases, binds at replication fork
• Topoisomerase


  Binds ahead of replication fork, breaks covalent bonds to relieve overwinding