Genetics 2

  1. Crossing over occurs during which phase of meiosis?
    Prophase 1
  2. The frequency of genetic recombination is inversely proportional to _________?
    The distance between the genes.

    That is, genes that are close in proximity rarely recombine - they tend to be inherited together.
  3. Which two genes are closest in proximity?

    recombination frequency
    y - w 0.010
    w - v 0.297
    v - c 0.030
    Genes "y" and "w" are closest in proximity since their recombination frequency is lowest (1%)

    Interpretation: "y" and "w" are 1 Centimorgan apart.
  4. Explain what is meant by the term "wild-type."
    A term that describes a genotype/phenotype that occurs normally in nature.
  5. Define a Three-point Cross study.
    These study three geens, with two alleles each (ex. A & a), that are close to each other on a chromosome; they all exhibit linkage when studied in pairs.
  6. Identify this type of cross-over:

    A B C
    a b c

    A B c
    a b C
    Single cross-over.
  7. Identify this type of cross-over:

    A B C
    a b c

    a B C
    A b c
    Single cross-over.
  8. Identify this type of cross-over:

    A B C
    a b c

    A b C
    a B c
    A double cross-over (a switch in the central gene).
  9. Which type of cross-over is the most rare? What does it determine?
    • A double cross-over.
    • It determines which gene is central in a Three-point Cross.
  10. In a Three-point Cross study,

    1.) Recombination frequencies determine______.
    2.) Rare double cross-overs determine______.
    • 1.) Distances
    • 2.) Sequence of genes (order)
  11. True or false:
    The physical and genetic map of a given chromosome should be identical.
    • False.
    • Certain biological processes can suppress certain parts of chromosomes (and their ability to recombine).
  12. Give examples of non-nuclear genes.
    • 1.) Genes in the circular DNA of mitochondria
    • 2.) Genes in the circular DNA of chloroplasts
  13. From whom are non-nuclear genes inherited?
    • The mother.
    • These are inherited with the cytoplasm of the egg.
    • These characteristics are therefore determined by the mother's genotype.
  14. Identify the 3 components of a nucleotide.
    Image Upload 1
  15. What category of bases is a two ring structure? A single ring structure? Name them.
    • 1.) Purines (Adenine, Guanine, Hypoxanthine)
    • 2.) Pyrimidines (Thymine, Cytosine, Uracil)
  16. Draw and number the structure of a purine.
    Image Upload 2
  17. Draw and number the structure of a pyrimidine.
    Image Upload 3
  18. Draw and number the structure of adenine.
    Image Upload 4
  19. Draw and number the structure of guanine.
    Image Upload 5
  20. Draw and number the structure of cytosine.
    Image Upload 6
  21. Draw and number the structure of uracil.
    Image Upload 7
  22. Draw and number the structure of thymine.
    Image Upload 8
  23. Draw and number the structure of deoxyribose.
    Image Upload 9
  24. Identify the following as a base, a ribonucleoside, or a ribonucleotide.

    1.) Uridine
    2.) Cytidylate
    3.) Guanine
    4.) Adenosine
    5.) Hypoxanthine
    6.) Inosine
    • 1.) Ribonucleoside ('ine)
    • 2.) Ribonucleotide ('ate)
    • 3.) Base
    • 4.) Ribonucleoside ('ine)
    • 5.) Base
    • 6.) Ribonucleoside ('ine)
  25. True or False?

    DNA / RNA is read 3' to 5'.
    False

    DNA / RNA is read 5' to 3', based on the sugar ribose.
  26. The glycosidic bond is located at which carbon on the purines? Pyrimidines?
    • 1.) Purines - Carbon #9
    • 2.) Pyrimidines - Carbon #1
  27. In DNA, how many bonds does the A-T complex form? The G-C complex?
    • 1.) 2 Hydrogen bonds
    • 2.) 3 Hydrogen bonds
  28. Are the hydrogens in the bases electron donors or acceptors?
    Electron donors.
  29. DNA normally forms which type of helix: A or B?
    DNA is most stable in the B-type helix, though under certain conditions it can take on the A-form.
  30. RNA forms which type of helix: A or B?
    RNA takes on the A-type helix.
Author
jdonaldson
ID
5091
Card Set
Genetics 2
Description
Genetics Exam 1 Material
Updated