Which one of the following statements about transport of nutrients in phloem is correct?
A) Solute particles are actively transported from phloem at the source.
B) Companion cells control the rate and direction of movement of phloem sap.
C) Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed.
D) A sink is the part of a plant where a particular solute is produced.
C
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Which of the following is most likely to be true about the mouse and rat myosin genes?
A. The nucleotide sequences are identical. B. The genes encode proteins with different functions. C. The genes are similar in sequence, but not identical. D. There is no homology between the two sequences. E. The genes encoding myosin closely resemble those encoding actins.
Which of the following statements about the lytic pathway is false? a. Viral genes instruct the cell to produce a viral enzyme that initiates lysis and releases new virus particles
b. After the viral genome is injected into the host cell, viral genes direct the cell to make viral DNA and proteins. c. The virus enters a latent state during which time it is integrated into the host cell membrane. d. The virus attaches to the host cell and injects DNA into it.
Which discipline is most directly applicable to most pharmaceutical drug trials?
a. genomics b. metabolomics c. proteomics d. systems biology
Which of the following are found on either side of a plant stoma?
a. guard cells b. trichomes c. leaves d. root hairs