PLANTS ARE MULTI-CELLULAR ORGANISMS WITH SPECIALIZED STRUCTURES

CELLS, TISSUES & SYSTEMS

COMPANION CELL

* A cell connected to & that appears to direct activities of sieve tube cells

* A type of cell found within the phloem of flowering plants. Each companion cell is usually closely associated with a sieve element. Its function is uncertain, though it appears to regulate the activity of the adjacent sieve element and to take part in loading and unloading sugar into the sieve element

CELLS, TISSUES & SYSTEMS

CUTICLE

* A waxy, waterproof coating on leaves & stems that prevents excess evaporation & helps the plant resist attack from micro-organisms

* A protective and waxy or hard layer covering the epidermis of a plant, invertebrate, or shell

CELLS, TISSUES & SYSTEMS

EPIDERMIS

* The outer layer of cells that covers all plants

* The outer layer of tissue in a plant, that forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, and absorbs water and mineral nutrients

CELLS, TISSUES & SYSTEMS

GROUND TISSUE

* Cells that make up the majority of the plant beneath the epidermis

* Ground tissue comprises the majority of a young plant and lies between the vascular and dermal tissues

CELLS, TISSUES & SYSTEMS

GUARD CELL

* A cell on the lower epidermis of leaves that forms an opening for gas exchange

* Are specialized plant cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore

CELLS, TISSUES & SYSTEMS

MERISTEM

* An area where cell division occurs, resulting in the growth of the plant

* Is a tissue in plants that consists of undifferentiated cells (meristematic cells) capable of cell division. Meristems give rise to various tissues and organs of a plant and are responsible for growth

CELLS, TISSUES & SYSTEMS

ORGAN

* Tissues grouped together performing the same functions

*  A group of tissues in a living organism that have been adapted to perform a specific function

CELLS, TISSUES & SYSTEMS

PHLOEM TISSUE

* Sieve tube cells that transport sugars from the leaves to other parts of the plant

* Phloem is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis 

CELLS, TISSUES & SYSTEMS

ROOT SYSTEM

* The part of the plant below the ground (one exception being aerial roots)

* The root system of a plant constantly provides the stems and leaves with water and dissolved minerals. In order to accomplish this the roots must grow into new regions of the soil. The growth and metabolism of the plant root system is supported by the process of photosynthesis occurring in the leaves

CELLS, TISSUES & SYSTEMS

SHOOT SYSTEM

* The part of the plant above ground (one exception being tubers)

* The shoot system consists of the stems and leaves of the plant. More specifically, it includes the nodes, inter-nodes, auxillary buds, terminal bud and leaves

CELLS, TISSUES & SYSTEMS

STOMATA

* Openings on the underside of leaves through which the exchange of gases occurs

* Are tiny openings or pores in plant tissue that allow for gas exchange. Stomata are typically found in plant leaves but can also be found in some stems. Specialized cells known as guard cells surround stomata and function to open and close stomatal pores

CELLS, TISSUES & SYSTEMS

TISSUE

* A group of cells performing the same function together

* Tissues are groups of cells that have a similar structure and act together to perform a specific function 

CELLS, TISSUES & SYSTEMS

VASCULAR BUNDLE

* A grouping of phloem & xylem along with other associated tissues

* A vascular bundle is a part of the transport system in vascular plants. The transport itself happens in vascular tissue, which exists in two forms: xylem and phloem. Both these tissues are present in a vascular bundle, which in addition will include supporting and protective tissues

CELLS, TISSUES & SYSTEMS

VASCULAR TISSUE

* Transport tissue formed of cells joined into tubes (phloem & xylem) that carries water & nutrients throughout the plant

* Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally

CELLS, TISSUES & SYSTEMS

XYLEM TISSUE

* Non-living tubes that move water & dissolved minerals up the stem from the roots to the leaves

* Xylem is one of the two types of transport tissue in vascular plants, phloem being the other. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients

CELLS, TISSUES & SYSTEMS

THE 3 MAIN TYPES OF PLANT TISSUE ARE:

1. Dermal tissue: the outer layer of cells that covers all non-woody plants & is responsible for the exchange of matter & gases

2. Cuticle

3. Ground tissue