The heart in a human embryo begins to beat

around ___ after fertilization.



a. 5 days
b. 3 weeks
c. 7 weeks
d. 9 weeks
e. 12 weeks


B

Biology & Microbiology

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Phorid flies are being used to combat the invasive red imported fire ants. How do phorid flies kill the ants?

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What is the difference between the leading strand and the lagging strand in DNA replication?

A) The leading strand is synthesized in the ? direction in a discontinuous fashion, while the lagging strand is synthesized in the ? direction in a continuous fashion. B) The leading strand is synthesized continuously in the ? direction, while the lagging strand is synthesized discontinuously in the ? direction. C) The leading strand requires an RNA primer, whereas the lagging strand does not. D) There are different DNA polymerases involved in elongation of the leading strand and the lagging strand.

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The pH indicator(s) in the Eosin Methylene Blue Agar is (are)

A. Neutral red B. Eosin Y & methylene blue C. Phenol red D. Methyl red E. Bile salts & brilliant green

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Simplexviruses can establish latent infections of ________ cells. 

A. B  B. epithelial  C. nerve D. T  E. muscle

Biology & Microbiology