Test 3

The flashcards below were created by user Chawk on FreezingBlue Flashcards.

  1. Mendel's First Law of Segregation
    • A sperm or egg carries only one allele for each inherited character bc allele pairs separate (segregate) from each other during the production of gametes. 
    • Also explains the 3:1 ratio in the F2 generation.
  2. Mendel's Second law of Independent Assortment
    Mendel suggested that the inheritance of one character has no effect on the inheritance of another.

    And that the dyhybrid cross is the equivalent to two monohybrid crosses.

    9:3:3:1 phenotype ratio
  3. Gregor Mendel
    in the 19th century he used garden peas and began the field of genetics.
  4. Pangenesis
    • "the blending theory" the idea that hereditary materials mix in forming offspring. 
    • later rejected bc it did not explain how traits that disappear in one generation can reappear in later generations.
  5. Aristotle
    rejected pangenesis and argued that instead of particles, potential to produce the traits was inherited.
  6. Heredity
    the transmission of traits from one generation to the next.
  7. Genetics
    scientific study of heredity
  8. Genes
    • Carry all DNA
    • They do not blend, they segregate
  9. Character
    A heritable feature that varies among individuals, such as a flower color.
  10. Trait
    Each variant for a character, such as purple or white flowers.
  11. Alleles
    Alternative versions of genes that account for variations in inherited characters.
  12. Homozygous Genotype
    Genotype that has identical alleles (PP)
  13. Heterozygous Genotype
    Genotype that has two different alleles (Pp)
  14. Dominant Allele
    Determines the organisms appearance if the alleles of an inherited pair differ.
  15. Recessive Allele
    There is no noticeable effect on the organisms appearance if the alleles of an inherited pair differ.
  16. Phenotype
    the appearance or expression of a trait.
  17. Genotype
    The genetic makeup of a trait.
  18. Punnett Square
    shows the four possible combinations of alleles that could occur when these gametes combine.
  19. Locus (Loci)
    The specific location of a gene along a chromosome.
  20. Dihybrid Cross
    • A mating of parental varieties that differ in two characters.
    • ie: seed color and shape
  21. Monohybrid
    • one character
    • ie: purple vs white
  22. Testcross
    • the mating between an individual of unknown genotype and a homozygous recessive individual.
    • Mendel used this to verify that he had true breeding genotypes.
  23. Pedigree
    • shows the inheritance of a trait in a family through multiple generations.
    • demonstrates dominant or recessive inheritance and can be used to deduce genotypes of family members.
  24. Recessive Inheritance
    • two recessive alleles are needed to show disease.
    • heterozygous parents are carriers of the disease causing allele.
    • the probability of inheritance increases with inbreeding, mating between close relatives.
  25. Dominant Inheritance
    • One dominant allele is needed to show disease.
    • dominant lethal alleles are usually eliminated from the population.
  26. Cystic Fibrosis
    • the most common fatal genetic disease in the US. 
    • it results in excessive thick mucus secretions.
    • the allele is recessive and chromosome #7 is in charge of it.
    • 1:20 are carriers
    • 1:2500 are child born
  27. What determines the sex of a baby?
    • designated X and Y sex chromosomes
    • males have XY
    • Females have XX
  28. Human sex linked disorders
    • a male receiving a single X linked recessive allele from his mother will have the disorder.
    • a female must receive the allele from both parents to be affected.
  29. Nucleotide
    • monomer of a nucleic acid
    • composed of a nitrogenous base, five carbon sugar, and phosphate group.
  30. DNA nucleotide nitrogen containing bases?
    • Adenine (A)
    • Cytosine(C)
    • Thymine (T)
    • Guanine (G)
  31. Difference bw DNA and RNA
    • Deoxy Ribonucleic Acid: Double Helix, ATCG, Genes
    • Ribonucleic Acid: single strand, AUCG, carry genes to make protein, mRNA, tRNA, rRNA in cytoplasm
  32. Transcription
    • The synthesis of RNA under the direction of RNA.
    • "copy" everything from DNA to RNA in nucleus
  33. Translation
    • The synthesis of proteins under the direction of RNA.
    • RNA to Protein in cytoplasm in the ribosome
  34. Triplet Code
  35. Codons
  36. Genetic Code
    • 60 plus 1 AUG codes for methionine and start of transcription.
    • 3 "stop" codons signal the end of translation. (UAA, UAG, UGA)
  37. Messenger RNA (mRNA)
    • carries all 64 codes
    • prokaryotes has no nucleus
    • eukaryotes exits in nucleus to cytoplasm and has introns and exons.
  38. Transfer RNA (tRNA)
Card Set
Test 3
Test 3 Notes
Show Answers