key concept 33.2 Plant Organs Are Made Up of Three Tissue Systems

By the end of embryogenesis, both the apical–basal and radial axes have been established. Unlike complex animals that can have dozens of different tissues (for example, in humans there are three kinds of muscle tissue alone), plants have just three major tissue systems, each of which has specialized cells.

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  • Ground tissue forms most of the plant body and includes parenchyma, collenchyma, and sclerenchyma. The dermal and vascular systems have parenchyma and sclerenchyma.

  • Vascular tissue consists of xylem and phloem, which are the plant’s transport system.

As Focus: Key Figure 33.6 illustrates, the three major plant tissue systems develop in a radial pattern in the embryo, establishing a concentric arrangement of dermal, ground, and vascular tissues. From these tissue systems will arise the roots, stems, and leaves of the adult vegetative plant body.

focus: key figure

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Figure 33.6 Three Tissue Systems Extend throughout the Plant Body The arrangement shown here is typical of eudicots, but the three tissue systems are continuous in the bodies of all vascular plants.

Question

Q:What is a major difference between cells in the ground tissue in the leaf compared to the root?

The leaf cells contain chloroplasts and carry out photosynthesis.