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Unformatted text preview: 3/5/09 1 The experiments of Mangold and Spemann in 1924, on transplantation of the dorsal lip of the newt gastrula, are arguably the most influential in the history of developmental biology. Hilde Mangold was a PhD student. She died in a house fire at age 26. Hans Spemann was awarded the Nobel Prize in 1935. He always referred to the work in his later publications as Hilde Mangolds experiment. Developmental Biology Cut-off Clicker question One quiz question is sooo long that the last sentence is cut off. Here is the full question: The disease, sickle-cell anemia (sickled human erythrocytes, below) is common in malaria-infested areas because individuals that are heterozygous for the gene (HbAHbS) have enhanced resistance to malaria over normal individuals (HbAHbA). Individuals with severe sickle-cell anemia (HbSHbS) usually die before reproduction. Assume that a population under Hardy-Weinberg equilibrium has allele frequencies of HbA = 0.8 and HbS = 0.2. Assume that this population is then subject to the following selection forces: HbAHbA 15% die of malaria HbAHbS 5% die of malaria HbSHbS 100% die of severe sickle-cell anemia What will be the frequency of the HbS allele after selection occurs? This is posted on the ANNOUNCEMENTS website Webquiz 18 is posted online. It is due on Sunday at midnight. If you are LECTURE ONLY.. Pick up your Prelim 4 bubble sheet from Mark Sarvary In a famous experiment in 1924, Mangold and Spemann transplanted a piece of the dorsal lip of a newt gastrula to the ventral side of a second gastrula. gastrula....
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