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BSC 219
Homework 1
Due 9/4/12
5 Total points
1. Briefly describe Mendel’s law of independent assortment and the
conditions to which it is limited. Independent assortment states that
any loci will be inherited by separate patterns from each other and
the inheritance of one will not affect the inheritance of the other. It
only applies if the loci are not physically linked on the same
chromosome.
2. Meiosis is divided into two phases Meiosis I and Meiosis II. Briefly
describe the result of each of these two phases. Meiosis I involves the
initial genetic reduction of 1x 2n cell to 2x 1n cells when homologs
are separated into sister cells. Meiosis II involves the separation of
sister chromatids from replicated chromosomes and results in 4x 1n
cells.
3. In a plant, oval leafs are dominant to round leafs, and yellow flowers are
dominant over white flowers. Assuming that you have a true-breeding line of
plants with oval leafs and yellow flowers, and another true-breeding line of
round leafs with white flowers, and assume that the two traits are not linked,
what would the phenotypic ratio’s be in the F1 generation? All would be
Oval and yellow.
4. In the experiment above, assume that you crossed F1xF1, what would the
phenotypic ratios be of the F2 generation.
9 Oval yellow
3 Oval white
3 round yellow
1 round white
5) The gene encoding red/green color blindness is X-linked recessive in
humans. Mallory is not colorblind, however, her father was. Mallory is
married to Rich who has normal color vision. What percentage of male
children born to Mallory and Rich would you expect to be colorblind?
What % of female children born to Mallory and Rich would you expect to be
colorblind? 50% of males would be expected to exhibit color-
blindness. 0% of daughters would be expected to exhibit colorblindness.