Genetics

Exploring DNA and how it's integral to life.

Chapters:
  • What is DNA?

    Understand the relationship of the structure and function of DNA to protein synthesis and the characteristics of an organism.

  • What is on our Genes?

    A gene is a piece of information passed from parents to offspring, and genes often are in different forms called alleles. For example, the gene for pea plant height has two alleles, tall and short.

  • How Do We Pass On Our Genes?

    Use the concepts of Mendelian and non-Mendelian genetics to explain inheritance. For example, incomplete dominance, independent assortment, sex-linked traits and linkage.

  • Why Do We Look Different?

    Changes in DNA are mutations which create variation between different organisms. When mutations happen in sex cells (sperm and eggs), they may be passed on to future generations and influence natural selection; mutations that occur in body cells may affect the cell or the entire organism.

  • Can We Change Our Genes?

    Analyze and investigate emerging scientific issues. For example, genetically modified food, stem cell research, genetic research and cloning.

  • How Do Traits Combine and Mix?

    Sorting, recombination, chi-square, dihybrid crosses, pleiotropy, epistasis, polygenetic traits, and linkage groups

OGT Questions:

  1. Color blindness is a sex-linked trait that is carried on the X chromosome. If a boy is born color-blind, what would have to be true?

    1. His father had normal vision.
    2. His grandmother was color-blind.
    3. His mother carried at least one gene for color blindness.
    4. His grandfather passed on the color-blind trait to his father.
  2. The pedigree below shows the inheritance pattern of a recessive allele (z) that results in a genetic disease.

    1. Zz
    2. ZZ and zz
    3. ZZ and Zz
    4. ZZ, Zz and zz

    Based on the inheritance pattern, what are all the possible genotypes for individual 6?

  3. Significant progress has been made in the development of oxygen-carrying solutions that may replace whole blood. Describe two reasons why researchers are so interested in developing artificial blood to replace the use of whole blood

    Respond in the space provided in your Answer Document. (2 points)

  4. A student takes a herbicide-resistant weed from plot 3 and a herbicide-resistant weed from plot 4. He determines that both plants have dominant mutations in the gene that is responsible for herbicide resistance (H). The genotype of each plant is indicated below.

    In a cross between these two weeds, what percentage of the offspring would be resistant to the herbicide?

    1. 0%
    2. 25%
    3. 50%
    4. 100%
  5. Geneticists have determined that the majority of individuals in an isolated island population have blood type B. Type A blood is found to be more common in the mainland population from which the island was settled.How could a geneticist best explain the dominance of blood type B in the island population?

    1. Random mutations have occurred in the island population.
    2. Genetic drift has reduced the frequency of type A individuals.
    3. Natural selection has only occurred in the mainland population.
    4. Environmental conditions on the island are less favorable for type B individuals.