53 terms

Plant cells, tissues, and organs

Most abundant type of cell in plants; spherical or elongated cells with thin flexible walls; most usually have a large central vacuole; sometimes contains fluid or sap; main functions are storage and food production
Cells thicker to provide support; irregular in shape; specialized for supporting regions of the plant that are still lengthening
Very thick rigid walls provide support; support and strengthen plant in areas where growth is no longer occurring; dead at maturity providing a frame if support
Plant tissues
Dermal vascular and ground
Dermal tissue
Forms the outside covering; epidermis is one of the layers; openings in the leaf and stem epidermis called stomata
composed of flattened parenchyma cells; covers all parts of the plant, tightly packed together and produces the waxy cuticle
openings in the cuticle that control the exchange of gases; guard cells control the opening and closing
root hairs
epidermis gives rise to; extentions are indiviual cells that help the root absorb water and minerals
epidermis gives rise to; on the stem and leaves of some plants, giving them a fuzzy apperance
vascular tissue
transport food, minerals, water throughout the plant; types are xylem and phloem
plant tissue composed of tube-shaped cells that transport warer and minerals upward; made up of tracheids and vessel elements which are cylindrical and dead at maturity (sclerenchyma);
vessel elements
better at doing their job than trachieds
in seedless vascular plants and in most gymnosperms
series of living tubular cells (sieve tube members) that transport sugars from the leaves to all parts of the plant; have companion cells the keep them ALIVE; parenchyma cells
companion cells
next to each parenchyma cells in the phloem; nucleated cells that help manage transport through the STM
sieve plates
the end walls between the two STM's in angiosperms
ground tissue
storage, metabolism and support; includes all tissues other than dermal and vascular; mainly composed of parenchyma cells but has collenchyma and sclerenchyma as well; fuctions- photosynthesis (leaves and stem) storage (stem and root) and support
Meristematic tissue
control growth; regions of actively dividing cells; small, spherical parenchyma cells with large nuclei
Apical meristem
found at or near the tips of the roots and stems; allow increase in length; PRIMARY GROWTH
Intercalary meristem
located above the bases of leaves and stem in some monocots; allow grass leaves to grow quickly after being mowed
lateral meristem
only found in gymnosperms and most dicots; found in roots and stems; allow an increase in width or diameter of a plant SECONDARY GROWTH; two types- Vascular cambium and cork cambium
vascular cambium
located between the xylem and phloem; produces new vascular tissue in the stems and leaves
cork cambium
located outside the phloem and produces cork; cork cells replace the epidermis in woody stems and roots; provides protection and prevents water loss
roots, stems, and leaves
underground parts of a plant; anchor plant to the ground; absorb water and nutrients(micronutrients and macronutrients) and transport these up to the stem; some may store food; types- tap, fibrous, and adventious
tap root
a central, fleshy root with smaller branch roots; DICOT
fibrous root
many roots branching from a central place; MONOCOT
adventious roots
roots that grow from unusual places; types-aerial and prop
aerial roots
cling to objects such as walls and provide support for climbing roots
prop roots
help support tall plants
root structures
root cap, epidermis, root hairs, xylem and phloem
root cap
protective coveringg on the apical meristem that produces a lubricating oil, making it easier for the root to penetrate soil
roots in dicots
xylem forms a central star-shaped mass with the phloem cells between
roots in monocots
strands of xylem alternate with phloem strands; usually have central core of parenchyma cells=pith (form in a circle)
above ground parts of plants that support leaves and flowers; two types-woody and herbaceous; function are to provide supports for all above ground parts, transport water, minerals ions, and sugars to and from the roots and leaves
short, thickened underground stems surrounded by leafy scales
swollen, underground stems that have buds that will sprout new plants
undergroound stems that store food
grow along soil surface and produce new plants
stems in dicots
xylem and phloem are arranged in circular bundles that form a ring in the cortex
stems in monocots
vascular bundles of xylen and phloem scattered throughout
he movement of carbs through a plant
primary function-photosynthesis; most are flat with good SA
leaf structure
epidermal layer, palisade mesophyll, spongy mesophyll and more of the epidermal layer
palisade mesophyll
made up of colums shaped cells containing many chloroplasts; found just under the upper epidermis layer which allows for max. exposure to the sun; most photosynthesis takes place here
spongy mesophyll
composed of loosely packed, irregularly shaped cells which are surrounded by many airspaces which allow carbon dioxide, oxygen, and water vapor to flow freely around the cells
loss of water through the stomata; the opening and closing of the guard cells regulate transpiration; causes plants to lose up to 90% of all water they transport from the roots
parrallel veins
branched veins
cactus spines
reduce water loss and protect from herbivores
food storage
enlarged fleshy leaf bases that cover bulbs
catching insects
venus fly trap