Explain how Curt Stern showed, using evidence from Drosophila, that genetic recombination is associated with the physical exchange of parts between homologous chromosomes
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In genetic crosses, carnation-colored eyes is a sex-linked recessive allele, and bar-shaped eyes is an incompletely dominant sex-linked allele caused by a deletion. Stern used male flies that had carnation eyes and normal eye shape, and thus a normal size X chromosome. He crossed those to heterozygous female flies that had a shortened Bar X- chromosome with carnation eye color and a second X that was a normal sized B+ chromosome with the wild-type (car+) eye color and a piece of the Y chromosome attached to the X with normal alleles of both genes. Male offspring that were recombinant with red-colored eyes in the bar shape had an X chromosome that was shorted and had a piece of the Y chromosome attached showing physical exchange on the X chromosome.
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Indicate whether the statement is true or false.
Which of the following processes is not a function of antibodies?
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Interference RNA technology is one of the most exciting new developments in genetics in recent years
In April 2004, Cancer Research UK and the Netherlands Cancer Institute announced creation of a 24,000-molecule iRNA library, designed to inactivate about 8,000 human genes. One hope for this library is its application in combating cancer. How might iRNA be implemented in cancer treatment?
The stages of meiosis I are virtually the same as the stages of mitosis. The one major difference is
a. the homologous chromosomes line up opposite each other during metaphase. b. there is no anaphase in meiosis I. c. there is no prophase in meiosis I. d. the homologous chromosomes line up next to each other during metaphase. e. the homologous chromosomes line up at opposite ends of the spindle equator.