AP BIOLOGY

Detailed explanation-1: -Photosynthesis produces glucose in the green parts of plants, which are often leaves. This is then converted into sucrose. The sucrose is transported around the plant in phloem vessels.

Detailed explanation-2: -Organic molecules such as sucrose and amino acids move from a source to a sink via phloem tubes in plants. The phloem is composed of living tissue called sieve tube members (lack a nucleus) that are joined end to end to form a tube that conducts food materials throughout the plant.

Detailed explanation-3: -Food and other organic substances (e.g., some plant hormones and even messenger RNAs) manufactured in the cells of the plant are transported in the phloem. Sugars (usually sucrose), amino acids and other organic molecules enter the sieve elements through plasmodesmata connecting them to adjacent companion cells.

Detailed explanation-4: -Nutrients are translocated in the phloem as solutes in a solution called phloem sap. The predominant nutrients translocated are sugars, amino acids, and minerals, with sugar being the most concentrated solute in the phloem sap.