A scientist observes that the height of a certain species of asters decreases as the altitude on a mountainside increases. She gathers seeds from samples at various altitudes, plants them in a uniform environment, and measures the height of the new plants. All of her experimental asters grow to approximately the same height. From this she concludes __________.
a. height is not a quantitative trait
b. the trend in height that she observed was due to genetic variation
c. the differences in the parent plants' heights were due to directional selection
d. the height variation she initially observed was an example of environmental influence
e. stabilizing selection was responsible for height differences in the parent plants
Answer: d. the height variation she initially observed was an example of environmental influence
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A human mother’s genes seem to influence brain development while a human father’s genes seem to influence growth. What does this imply?
A. The mother imprints her brain development genes and the father imprints his growth genes. B. The mother imprints her growth genes and the father imprints his brain development genes. C. Mothers and fathers both imprint brain development genes. D. Brain development genes are present in the mitochondria, while growth genes are present in the nucleus. E. Brain development genes are on the X chromosome and growth genes are on the Y chromosome.
__________ contains protein-digesting enzymes and acid. Fill in the blank(s) with the appropriate word(s)
Which of the following groups do not contain any species that are autotrophs?
A. Bacteria B. Protista C. Plants D. Archaea E. Fungi
You have isolated a piece of DNA that you believe contains an interesting gene. Using a mix of RNA polymerase and ribonucleotides, you perform in vitro transcription
However, even though all of your controls work, no mRNA is created from your DNA fragment. Working backward, you note that your DNA preparation removed approximately 250 base pairs from the 5' end of the gene. The most likely explanation is that during DNA preparation A) the termination signal was removed. B) the RNA polymerase became inactivated. C) the 5' methyl guanosine cap was removed. D) the promoter was removed. E) None of these explains the negative results.