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Plants are placed into two simple kingdom subsections: nonvascular and vascular plants. The big distinction between the two groups is that vascular plants have vascular_tissues: tissues that conduct water and dissolved food in the plant body. The vascular tissues include xylem, which moves water and minerals upward through the plant and phloem, which moves dissolved food downward in the plant.
Nonvascular plants lack these tubes, and therefore must be small and thin so that each cell can acquire its needed materials via passive_transport from the plant's surface, or from other cells within the plant that are located near the surface.
Regardless of whether a plant is vascular or nonvascular, it has structures that (1) anchor it into the soil, (2) provide physical support for its photosynthetic structures, and (3) specialize in performing photosynthesis.
The difference is that in nonvascular plants these structures are called root-like, stem-like, and leaf-like because they lack vascular tissues. True roots, stems, and leaves are those body structures that contain vascular tissues.
Marchantia is a small nonvascular (Liverwort) plant that exhibits alternation_of_generations.
The male reproductive organs are physically supported by a sterile tissue unit called the antheridiophore. The expanded surface of the antheridiophore is often called the splash_platform. Rainfall landing on the platform surface assists with the distribution of sperm. The antheridia (sing: antheridium) located within the antheridiophore are the reproductive organs that produce the sperm. A sterile_jacket surrounds and protects each antheridium. A stalk also assists with support of each antheridium, as well as housing the sperm_canal that connects the antheridium to the splash platform.
The female reproductive organs (the archegonia) are supported by a sterile tissue named the archegoniophore. Rhizoids are cellular extentions that help anchor the structure. They are similar to the rhizoids of the fungi.
Microslides from tray D-8 have a cross-section of a single thallus. Micrographs 41C and 41D are both cross-sections of a single thallus. They are just different magnifications. Both 41C and 41D show the air_pores, rhizoids (root-like structures that act as anchors), and scales (thickened support areas).
Photo Atlas micrograph 41B shows a surface view of one entire Marchantia thallus with gemma_cups (pl: gemmae). Each gemma cup contains many gemmae, and each of the gemmae has the potential to develop into a new thallus.
We do not have a microslide that shows a surface view (wm) such as photograph 41B, but we do have slides with cross sections of a thallus revealing several gemma cups.
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