Which of the following supports the finding that sugar translocation in phloem is an active (energy-requiring) process?
A) Sucrose occurs in higher concentrations in companion cells than in the mesophyll cells where it is produced.
B) Movement of water occurs from xylem to phloem and back again.
C) Strong pH differences exist between the cytoplasm of the companion cell and the mesophyll cell.
D) ATPases are abundant in the plasma membranes of the mesophyll cells.
A
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Insertion of two bases into the coding region of a gene just after the start codon of a gene will result in a ____
mutation.
a. missense b. chromosomal c. frameshift d. silent e. nonsense
What tissue comprises the outer bark of woody plants?
a. ground tissue b. epidermis c. phloem d. periderm e. xylem
According to Woods, the key to understanding feelings of hunger is to appreciate that eating meals:
(a) results in satiety (b) stresses the body (c) often leads to a conditioned aversion (d) satisfies the body
A founder event changes allele frequencies because:
a. only a subset of genes in the original population are observed in the founder population. b. of random sampling of alleles from the original population. c. of the coalescent process. d. A and B. e. All of the above.