Drosophila melanogaster, the fruit fly, has a 2
n chromosome number of 8. Assume that you are microscopically examining the mitotic and meiotic cells of this organism. You note that in the female, two chromosomal pairs are metacentric and two pairs are acrocentric.
(a) Draw the chromosomal configurations as you would expect to see them at the stages listed:
| mitotic metaphase | first polar body (metaphase) |
| primary oocyte (metaphase) | ootid (G1) |
secondary oocyte (metaphase)
(b) Given that the previously mentioned cells are from individuals heterozygous for two independently segregating, autosomal loci,
plum eyes and
curled wings, place appropriate symbols (of your designation) on chromosomes in the drawings you made for part (a). Assume no crossing over, and there may be more than one correct answer in some cases.
(c) Assuming that a somatic G2 nucleus from the individuals mentioned above contains about 8.0 picograms of DNA, how much nuclear DNA would you expect in each of the cells mentioned in part (a)?
Chromosome structure.
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Chromosome Combinations
DNA sequence variation in parts of the Drosophila Adh gene
Standardized human chromosome banding patterns