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AP Biology – Free Response Questions – Unit 6, Meiosis and HeredityDias, ECFHSA) Describe the purpose of meiosis. Include a basic description of crossing over, and the evolutionary benefit.2. Thomas Hunt Morgan discovered that in fruit flies, the genes for body color (b), cinnabar eyes (cn), and vestigial wings (vg) were on the same chromosome. He noticed that 9% of the time, the b and cn genes were recombinant, and the cn and vg genes were recombinant 9.5% of the time. The b and vg genes recombined about 17%. Explain the cause of this, and draw a linkage map of these genes, showing the number of map units between them. Also give a one-sentence explanation of the relationship between the recombination frequency of two genes and the distance between them.3. Red-green colorblindness is a human disorder that is due to a sex-linked recessive allele. This disorder occurs almost entirely in males.(a) Why do recessive sex-linked traits occur more frequently in males than in females?(b) If Ariana is heterozygous for this condition and Tom is not color blind, what is the probability that they will have a son that is color blind? Show your work.4. In lab a student counts corn kernel phenotypes to learn about heredity. He looks at two genes: one is for color, where the presence of the dominant allele “P” deposits anthocyanin in the aleurone of the seed, causing a purple color. The recessive form of the allele (p) disrupts coloration and allows the yellow endosperm beneath to be visible. The second gene controls the starch content of seeds, which can make the seeds appear round in the dominant condition (R), or wrinkled in the recessive form (r). The ear of corn being studied is advertised to be from a cross between a plant heterozygous for both traits, and another plant heterozygous for color and with wrinkled seeds. List the genotypes of the parents, and what they could pass in their gametes. Also give the phenotype ratio of offspring, showing your work either by a Punnett square or mathematically. Purple, RoundPurple, WrinkledYellow,RoundYellow, WrinkledNumber37281610RatioThe table gives the actual counts the student got for each phenotype. Perform a chi-squared test to determine whether the student should accept the advertised genotypes of the parent corn. Finally, state your conclusion based on your results. You may use a null hypothesis for this. 32169102159000(Note: Use error margin of 5%, i.e. P=.0570231017716500 ................
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