Cell And Tissues Flashcards
What is a parenchyma cell and what tissues are they generally found in?
Parenchyma cells are the most numerous in the plant body. They create masses of parenchyma tissue in the cortex, pith of stems and roots, and in leaf mesophyll. They also occur as vertical strands of tissues and as horizontal strands called rays in the secondary vascular tissue.
What are the three cell types found in plant cells?
Parenchyma, sclerenchyma, and chlorenchyma.
What are sclerenchyma cells and where can you find them?
Sclerenchyma cells are thickened by often lignified secondary walls and they are important for strengthening and supporting elements in plant parts that have ceased elongating.
There are 2 types: fibers and sclereids.
What are fibers?
Fibers are sclerenchyma cells that are generally long and slender, occurring in strands or bundles.
What are sclereids?
Sclereids are a type of sclerenchyma cells that are variable in shape and are often branched. They are shorter than fibers and may occur singly or aggregately in ground tissue as well as seed coats, shells and endocarps of fruits.
What are chlorenchyma cells and where can they be found?
Collenchyma cells, like parenchyma, are alive at maturity. They are typically unevenly thickened and have non-lignified primary cell walls. They occur in discrete strands or continuous cylinders just below the epidermis in stems and petioles.
What is an apical meristem?
Apical meristems are found at the tips of all roots and stems and are involved primarily with the extension of the plant body.
It is composed of three primary meristems: protoderm, procambium, and ground meristem, which are all initiated in embryogenesis.
What is protoderm?
Protoderm is a primary meristem that gives rise to the epidermis (primary tissue).
What is the ground meristem?
The ground meristem is a primary meristem that gives rise to the ground tissues: parenchyma, sclerenchyma, collenchyma (ground tissue system).
What is the procambium?
The procambium is a primary meristem that his rise to the primary xylem and phloem (vascular tissue system).
What are the three tissue systems of the plant body?
Dermal tissue system, ground tissue system, and vascular tissue system.
What are the two types of tracheary elements?
Tracheids and vessel elements. They are both elongated cells with secondary walls and lack protoplasts at maturity, but vessel elements contain perforations or “perforation plates,” which are areas lacking both primary and secondary walls.
What are the cell types found in xylem tissue and their functions?
Tracheary elements (tracheids and vessel elements): function in conduction of water and minerals. Fibers: function in support, some storage. Parenchyma: function in storage.
What are the cell types found in phloem tissues and what are their functions?
Seive elements (seive cells and seive-tube elements): function in the long distance transport of food. Sclerenchyma (fibers, sclereids): function in support, sometimes storage. Parenchyma: function in storage.
