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 2
  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 4
  17. Draw and number the structure of a pyrimidine.
    Image Upload 6
  18. Draw and number the structure of adenine.
    Image Upload 8
  19. Draw and number the structure of guanine.
    Image Upload 10
  20. Draw and number the structure of cytosine.
    Image Upload 12
  21. Draw and number the structure of uracil.
    Image Upload 14
  22. Draw and number the structure of thymine.
    Image Upload 16
  23. Draw and number the structure of deoxyribose.
    Image Upload 18
  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