primary phloem
Quick Summary
Primary phloem is the first phloem tissue to form in a plant, developing from apical meristems in root and shoot tips. It is a type of plant vascular tissue responsible for transporting sugars produced during photosynthesis from the leaves to other parts of the plant.12
Primary phloem consists of sieve elements, phloem fibers, and parenchyma cells. Sieve tubes, formed by sieve tube cells, are the main channels for this food transport. Companion cells assist sieve elements with their cellular functions, while phloem fibers provide tensile strength. Primary phloem can be further divided into protophloem, which matures before plant elongation, and metaphloem, which matures after elongation. Protophloem sieve tubes may be destroyed as the plant grows, while metaphloem can persist or be replaced by secondary phloem in plants with a cambium.2
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angiospermOrganization of the vascular tissueThe primary phloem (Figure 6) is composed of sieve elements and fibers. Parenchyma cells are interspersed throughout. Sieve elements are longitudinal cells that transport food. They are composed of sieve cells and sieve-tube members. Sieve-tube members have clusters of pores in the cell walls known as…
Read MoreThe primary phloem (Figure 6) is composed of sieve elements and fibers. Parenchyma cells are interspersed throughout. Sieve elements are longitudinal cells that transport food. They are composed of sieve cells and sieve-tube members. Sieve-tube members have clusters of pores in the cell walls known as…
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…of the primary xylem and phloem is called a collateral bundle; the outer portion of the procambium (adjacent to the cortex) becomes phloem, and the inner portion (adjacent to the pith) becomes xylem. In a bicollateral bundle, the phloem is both outside and inside the xylem, as in Solanaceae (the…
Read More…of the primary xylem and phloem is called a collateral bundle; the outer portion of the procambium (adjacent to the cortex) becomes phloem, and the inner portion (adjacent to the pith) becomes xylem. In a bicollateral bundle, the phloem is both outside and inside the xylem, as in Solanaceae (the…
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treeGeneral features of the tree body…of the column and the primary phloem toward the outer aspect. The multiple vascular cylinders are arranged throughout the cortex, either in an uninterrupted ring between the cortex and pith or separated from each other by ground tissues. In some monocotyledons the vascular cylinders are scattered throughout the stem. Regardless…
Read More…of the column and the primary phloem toward the outer aspect. The multiple vascular cylinders are arranged throughout the cortex, either in an uninterrupted ring between the cortex and pith or separated from each other by ground tissues. In some monocotyledons the vascular cylinders are scattered throughout the stem. Regardless…
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