Researchers in Alaska were interested in increasing the sockeye salmon (Oncorhynchus nerka) population in three coastal lakes. To accomplish this, the ponds were treated with fertilizers. As a result, zooplankton biomass increased between 40% and 700% in the three lakes. The substantial growth in zooplankton would suggest that prior to these experiments, these lakes were ________.

A. subject to low light levels
B. stratified
C. oligotrophic
D. eutrophic


Answer: C

Biology & Microbiology

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Which of the following serves as a switching mechanism in the photoperiodic response in plants?

a. phytochrome b. auxin c. cryptochrome d. calmodulin e. phytoalexin

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The photoreceptors of an earthworm are

located

a. on short antennae. b. on their body surface. c. in their eyes. d. near the tip of their tail. e. nowhere- earthworms do not have photoreceptors.

Biology & Microbiology

In Drosophila, the allele red eyes (bw+) is dominant to the allele for brown eyes (bw).  At another gene locus on the same chromosome, the allele for thin wing veins (hv+) is dominant to the allele for heavy wing veins (hv). Flies homozygous for bw and hv+ are crossed to flies homozygous for bw+ and hv to obtain doubly heterozygous F1 progeny.What would be the results of a test cross with the F1 flies?

A. 1 brown eye, thin wing veins: 1 red eye, heavy wing veins B. 1 brown eye, heavy wing veins: 2 red eye, thin wing veins: 1 red eye, thin wing veins C. 1 brown eye, thin wing veins: 2 red eye, thin wing veins: 1 red eye, heavy wing veins D. 1 brown eye, heavy wing veins: 1 red eye, thin wing veins

Biology & Microbiology

The start codon for translation is

A. AGU. B. AUG. C. AAA. D. UAA. E. UAG.

Biology & Microbiology