Explain how dissolved sugar is transported in the phloem by means of a pressure gradient. What will be an ideal response?


Concepts to Consider: At the source, a proton pump moves H+ out of sieve tube members,
causing active transport of sugar into sieve tube members. Water moves by osmosis into
sieve tubes, and hydrostatic pressure increases inside them. At the sink, sugar is transported
out of sieve tube members, with water following. Thus, hydrostatic pressure decreases within
the sieve tubes from source to sink. Hence, sugar moves between the source and sink as it
flows along the pressure gradient.

Biology & Microbiology

You might also like to view...

In animals, meiosis produces __________, and in plants, meiosis produces __________

a. gametes; gametes b. gametes; spores c. spores; gametes d. spores; spores

Biology & Microbiology

An individual's set of unique _____ can be used as a DNA profile

a. DNA sequences b. short tandem repeats c. SNPs d. all of these

Biology & Microbiology

For which of the following pHs, is the

hydroxide ion concentration greater than the hydrogen ion concentration?

a. 1 b. 3 c. 5 d. 7 e. 9

Biology & Microbiology

During implantation, the __________ buries itself in the uterine wall

ANSWER: blastocyst Fill in the blank(s) with the appropriate word(s).

Biology & Microbiology