Which of the following structures DOES NOT occur in a series of successive segments of an earthworm?

A. crop
B. nerve cord
C. setae
D. circular muscles
E. metanephridia


A. crop

Biology & Microbiology

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Which of the following conclusions can be made if two identical insertion sequences are identified in separate locations on a chromosome?

A. The insertion sequence was transferred via simple transposition. B. The insertion sequence was a "cut-and-paste" transposon. C. A mutation occurred during transposition of the insertion sequence. D. The insertion sequence was transferred via replicative transposition.

Biology & Microbiology

A fragment of DNA or RNA, labeled with a tracer, used for genetic studies is called a ________

a. probe b. genome c. cloning vector d. chromosome e. nucleotide

Biology & Microbiology

In terrestrial and shallow-water ecosystems, the grazing food chain is dominant over the detrital food chain

Indicate whether the statement is true or false

Biology & Microbiology

Which of the following versions of the polio vaccine is preferred in the United States?

A) oral polio vaccine which is made up of an attenuated viral strain B) antibiotic treatment to clear the infection C) transgenic DNA vaccine, which is made by inserting DNA for polio capsid proteins into the genome of a nonvirulent virus D) inactivated polio vaccine which is injected into muscle and requires several boosters E) Currently no vaccine is available, and patient isolation is the preferred method of control.

Biology & Microbiology