The translocation of organic solutes in sieve tube members is supported by
1. Root pressure and transpiration pull
2. P-proteins
3. Mass flow involving a carrier and ATP
4. Cytoplasmic streaming

Which of the following will always be a “sink” in a plant?

Identify the incorrect statement regarding xylem:
1. Xylem tracheids and vessels perform their vital function only after their death.
2. Tracheids have a strong cell wall deposited with cellulose fibrils forming thickened rings or spirals.
3. Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules.
4. Mass flow translocation between the source and the sink occurs due to a turgor pressure gradient.

For most plants, in late spring, phloem transports:
1. amino acids from the root source to the symbiotic fungal sink.
2. sugars from the leaf source to the apical meristem sink.
3. nucleic acids from the flower source to the root sink.
4. sugars from the stem source to the root sink.

Translocation in phloem always occurs from:
1. Sugar source to a sugar sink
2. Sugar sink to a sugar source
3. Leaf to a root
4. Leaf to xylem and then to phloem