In Cameroon, seedcrackers have either small bills (adapted for feeding on soft sedge seeds) or large bills (adapted for
feeding on hard sedge seeds). During competition for scarce resources, these birds primarily feed on the seeds for which
they are best adapted. This is an example of ____ selection.
a. stabilizing
b. disruptive
c. frequent
d. directional
e. mutational
ANSWER: b
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From which chamber of the heart does the right ventricle receive blood?
(a) right atrium. (b) left atrium. (c) left ventricle. (d) none of the above.
Three disadvantages of utilizing microarrays for transcriptome analysis are that microarrays (select all correct choices):
A. require large quantities of RNA to hybridize and thus show a positive signal. B. show high levels of nonspecific (background) hybridization. C. may not have DNA to which specific RNAs will hybridize. D. will not allow comparison of transcription between cell types. E. do not accurately report transcriptional levels of specific mRNAS. F. are not able to detect and evaluate rare allele variant transcripts.
Connective tissue
A. receives, generates, and conducts electrical signals throughout the body B. is rich in extracellular matrix C. generates force that facilitates movement D. forms continuous sheets that line body surfaces E. is composed of cells held together by tight junctions
"Knockout" mutants have had the activities of certain genes eliminated, which can aid the researchers in determining the effects of those genes on physiology, development, and other functions
Indicate whether the statement is true or false