AP BIOLOGY

Detailed explanation-1: -The phloem transport system transports sugar and is made of cells that are not lignified. The phloem transport system transports minerals and is made of cells that are not lignified.

Detailed explanation-2: -Detailed Solution. The correct answer is Phloem transports photosynthetic products. Phloem is a living tissue in vascular plants that conducts the soluble organic compounds synthesized downwards from the leaves during photosynthesis. Hence option 2 is correct.

Detailed explanation-3: -The mechanism by which sugars are transported through the phloem, from sources to sinks, is called pressure flow. At the sources (usually the leaves), sugar molecules are moved into the sieve elements (phloem cells) through active transport.

Detailed explanation-4: -The basic elements of phloem are fibers, sieve tubes, sieve cells, parenchyma, and companion cells. Lignin is not present in the conducting cells or sieve tubes because they are living structures.

Detailed explanation-5: -Which of the following is a correct statement about sugar movement in phloem? Sugar transport does not require energy. Sugar is translocated from sinks to sources.