Transport systems
Lesson Flashcards: Structure of the Stem Biology
Systems that move required substances around an organism’s body
Medullary rays
Regions of parenchyma tissue between the vascular bundles in dicots that mainly function as storage tissue and also transport materials from the vascular bundles to the pith for storage
Sclerenchyma
A tissue consisting of rigid, thick-walled, and lignified cells that provide strength and mechanical support in stems and leaves
Pith
A spongy central tissue in dicot stems that mainly functions as a storage tissue
Xylem
A vascular tissue in plants that transports water and dissolved mineral ions from the roots to the other parts of the plant
Collenchyma cells
Long cells with thick cell walls found under the epidermis and that provide support, structure, and flexibility to the plant
Cambium
A layer of meristematic cells between the xylem and phloem tissues in dicots
Monocot
A plant that produces seeds containing one cotyledon that serves as a food store for the plant embryo and later develops into the first leaf upon germination
Meristematic cells
Actively dividing, unspecialized plant cells
Waxy cuticle
A waterproof layer containing cutin that covers plant structures (e.g., leaves, stem) to minimize water loss from the plant by evaporation, protects the structure from mechanical damage, and helps to prevent the entrance of microorganisms that may cause infection
Cotyledons
A seed’s food stores that provide nutrients to the developing plant embryo during germination and will eventually form the plant’s first leaves
Vascular bundle
A part of a plant’s transport system that is primarily made up of xylem and phloem tissues
Parenchyma cells
Thin-walled cells that make up the bulk of the inside of nonwoody plant structures, such as leaves, stems, and roots
Stem
A long, stalk-like structure that forms the main body of a plant, plays a major role in the plant’s support and movement, and contains elements that allow the transport of essential substances
Endodermis (starch sheath)
The innermost cortex layer that functions to store starch and regulate the movement of water, ions, and plant hormones in the plant’s transport system
Dicot
A plant that produces seeds containing two cotyledons that serve as food stores for the plant embryo and later develop into the first leaves upon germination
Pericycle
A region that is filled with parenchyma cells or sclerenchyma fiber cells that surround the vascular bundles and support them by holding the xylem and phloem tubes upright
Cortex
An outer layer of tissue located between the epidermis and the vascular tissue of a stem or root
Epidermis
A single layer of cells covering a plant’s leaves, flowers, roots, and stems, forming a boundary to the external environment