The gradient distributions of alleles across continents reflect _____
a. the delineation of new races
b. genetic drift
c. human migration patterns
d. protective alleles
e. natural selection
c
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Identical copies of genes that can be transcribed simultaneously are called
A. segmental duplications. B. pseudogenes. C. tandem clusters. D. multigene families. E. expressed sequences.
Which is/are true regarding organic acids?
A. They are weak acids. B. They are often involved in metabolic reactions. C. They often exist in the ionized form at the near-neutral pH found in a cell. D. Pyruvate and pyruvic acid refer to different forms of the same substance. E. All of the choices are true.
Assuming that a particular disorder is caused by an allele of a single gene, what feature of a pedigree would allow one to conclude that the disorder was caused by a dominant allele?
A. Two unaffected parents have an affected child. B. Two affected parents have an unaffected child. C. An affected mother only has affected sons. D. All of the descendants of a particular affected person are also affected
In Drosophila melanogaster there is a sex-linked gene for eye color that is found only on the X
chromosome. The allele for red eye color (Xw+) is dominant over the allele for white eye color (Xw). You examine a vial of 100 flies that are all offspring from a single genetic cross. You see only redeyed females present, but you see both red-eyed and white-eyed males present. The genotypes of the parents were
a. Xw+Xw+; Xw+Y. b. XwXw; Xw+Y. c. Xw+Xw; XwY. d. Xw+Xw; Xw+Y. e. XwXw; XwY.