Question 1 - Trichomes are small plant hairs. The first graph represents the distribution of trichomes along the petiole (stem) of the first true leaf in a population of Wisconsin Fastplants (Brassica rapa). These plant self to produce the second generation. Which pattern of inheritance would most likely lead to results such as these?
Question 2 - Red/green color blindness in humans is a X-linked recessive trait. John and Natasha have normal vision. After 10 years of marriage Natasha gives birth to a color blind daughter. John files for divorce, claiming he is not the child's father. Is he justified?
Question 3 - A short-whiskered mutant was discovered in rabbits. When this mutant is crossed to a long-whiskered rabbit, 4 offspring had short whiskers and 3 had long ones. Two of these short-whiskered offspring mate, producing 6 short- and 3 long-whiskered rabbits. Mating of short-whiskered offspring mate in a number of subsequent generations, yielding similar segregation ratios. How is this trait inherited?
Question 4 - Explain the Inheritance ...
In Drosophila, two genes affecting body color are known. A mutant allele at one locus prevents the formation of granules on which pigment is laid down. An absence of these granules causes an albino. Another gene causes the color (the pigment involved) to be blood-red. True-breeding albino males were crossed to true-breeding blood-red females. All males and females in the resulting F1 generation were wild type in appearance. Two F1 flies were intercrossed, producing a large F2 generation, with the following phenotypes:
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Phenotypes
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Observations
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Wilt-type female
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60
|
78
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Blood female
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20
|
16
|
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Wild-type male
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30
|
26
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Albino male
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40
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34
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Blood male
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10
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6
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Total:
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160
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160
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Question 5 - Above are two pedigrees for the same trait. What is the most likely mode of inheritance for this trait?