CSET 119: Genetics and Evolution

  1. Explain the inheritance of traits which are determined by one or more genes, including dominance, recessive, sex linkage, phenotypes, genotypes and incomplete dominance
    • dominance - if two alleles of an inherited pair differ, determines the organism's appearance
    • recessive - has no noticeable effect on the organism's appearancephenotype - physical traits
    • genotype - genetic makeup
    • sex linkage - a gene located on a sex chromosome
    • incomplete dominance - an appearance between the phenotypes of the two parents
  2. Solve problems that illustrate monohybrid and dihybrid crosses
    • monohybrid - a mating of individuals differing at one genetic locus
    • dihybrid - a mating of individuals differing at two genetic loci
  3. Compare sexual and asexual reproduction
    • sexual:
    • creation of offspring by the fusion of gametes
    • increases genetic variability

    • asexual: offspring are genetically identical to lone parent
    • no need for mate
    • quicker and less energy in the production of gametes
    • produces genetically uniform populations
  4. Explain how the coding of DNA controls the expression of traits by genes
    • the sequence of nucleotide bases in DNA contains 3-base codons that code for amino acids for protein synthesis
    • traits arise from the actions of a wide variety of proteins
  5. Define mutations and explain their causes
    • any change in the nucleotide sequence of DNA
    • caused by errors during DNA replication or recombination
    • chemical or physical mutagens
  6. Explain the process of DNA replication
    • begins at origins of replication
    • semi-conservative - two strands of parental DNA separate and each becomes a template for the assembly of a complementary strand from a supply of free nucleotides
    • the nucleotides are lined up one at a time along the template strand in accordance to base pairing rules
    • enzymes link the nucleotides to form the new DNA strands
  7. Describe evidence, past and present, that supports the theory of evolution, including diagramming relationships that demonstrate shared characteristics of fossil and living organisms
    • the fossil record - the ordered sequence of fossils as they appear in the rock layers, marking the passage of geologic time biogeography - geographic distribution of species, we find species where they are because they evolved from ancestors that inhabited those regions
    • comparative anatomy - the comparison of body structures in different species, certain anatomical similarities among species are signs of evolutionary history 
    • comparative embryology - comparing early stages of development in different animal species reveals additional homologies not visible in adult organisms 
    • molecular biology - if two species have genes with DNA sequences that match closely, biologists conclude that these sequences are homologous and must have been inherited from a relatively recent common ancestor
  8. Explain the theory of natural selection, including adaptation, speciation and extinction
    • individuals whose inherited traits are best suited to the local environment are more likely than less fit individuals to survive and reproduce 
    • the individuals that function best should leave the most surviving offspring 
    • when challenged with a new environmental problem a population either adapts through natural selection, dies off in extinction or populations that do survive may change enough to become a new species in speciation
  9. List major events that affected the evolution of life on Earth (eg climate changes, asteroid impacts)
    • asteroid impacts: have caused the destruction of vast areas of inhabitants that lead the to the mass extinction of many kinds of organisms 
    • volcanic eruptions: ash can blanket land and water that blocks light needed for light, ash also effects chemical makeup of oceans
    • rapid climate change: likely from massive volcanic explosions, decrease in overall temperature affecting plant and animal life 
    • continental drift: movement of continents altered global distribution of species
Card Set
CSET 119: Genetics and Evolution
Science CSET