Bio Ch 24 Flashcards
Root system
consists of the roots of the plant
Shoot system
consists of stems and leaves
Vegetative Organs
structures that contain different tissues and perform one or more specific functions that allow them to live and grow; roots, stems, leaves; concerned with growth and nutrition, not reproduction
Perennial
plants that have vegetative structures that live year after year
Stem
main axis of a plant; has a terminal bud that allows it to elongate and produce new leaves
Node
occurs where leaves are attached to the stem
Internode
region between the nodes
Axillary bud
located at a node in the upper angle between the leaf and the stem; can produce new branches of the stem (or flowers)
Leaves
part of a plant that generally carries on the majority of photosynthesis
Evergreens
plants that bear leaves the entire year
Deciduous
plants that lose all of their leaves at the end of their growing season
Blade
wide portion of a foliage leaf
Petiole
stalk that attaches the blade to the stem
Monocots (monocotyledons)
plants with a seed containing only 1 cotyledon, which acts as transport tissue
Eudicots (eudiotyledons)
plants with seeds that contain 2 cotyledons, which supply nutrients to seedlings
Apical meristems
located at or near the tips of stems and roots, where they increase the length of these structures (primary growth)
Meristem
undifferentiated embryonic tissue in the active growth regions of plants; intercalary type allows plants to regrow lost parts
Epidermal tissue
forms the outer protective covering of a plant
Ground tissue
fills the interior of a plant
Vascular tissue
transports water and nutrients within the plant as well as providing support
Epidermis
closely packed epidermal cells which covers the entire body of both nonwoody (herbaceous) and young woody plants
Cuticle
wall of epidermal cells exposed to air; waxy to minimize water loss; also protects against bacteria and other organisms that might cause disease
Root hairs
certain epidermal cells have these long, slender projections; increase the surface area of the root for absorption of water and minerals as well as anchoring the plant to various substrates
Trichomes
on stems, leaves, and reproductive organs, epidermal cells produce hairs called these that have 2 important functions - to protect the plant from too much sun and to conserve moisture
Stomata (sing., stoma)
guard cells (epidermal cells with chloroplasts) surround the microscopic pores called this; when these are open, gas exchange and water loss occurs
Periderm
in older woody plants, the epidermis of the stem is replaced by this
Cork
majority component of periderm are these boxlike cells
Cork cambium
new cork cells are made by a meristem called this
Parenchyma
most abundant, typical plant cell; least specialized; found in all the organs of a plant; may contain chloroplasts and carry on photosynthesis or may contain colorless plastids that store the products of photosynthesis
Collenchyma
cells like parenchyma except with thicker primary walls; thickness is uneven, usually involves the corners of the cell; give flexible support to immature regions of a plant body
Sclerenchyma
cells with thick secondary cell walls impregnated with lignin
Lignin
highly resistant organic substance that makes the walls tough and hard; most are nonliving; primary function is to support mature regions of the plant; two types - fibers and sclereids
Xylem
type of vascular (transport) tissue that transports water and minerals from the roots to the leaves
Phloem
type of vascular tissue that transports sucrose and other organic compounds, usually from the leaves to the roots
Complex tissues
xylem and phloem are considered these because they are composed of two or more kinds of cells
Vessel elements
large. may have perforation plates in their end walls, arranged to form a continuous vessel for water and mineral transport
Tracheids
has tapered ends, form a less obvious means of transport; water can move across the end walls and side walls because of pits
Pits
depressions where a secondary wall does not form
Sieve-tube members
specialized parenchyma cells which serve as the conducting cells of phloem; arranged to form a sieve tube; contain cytoplasm but no nuclei
Vascular cylinder
in the roots, this is where vascular tissue is located
Vascular bundles
in the stem, vascular tissue forms these
Leaf veins
in the leaves, vascular tissue forms these
Root apical meristem
region protected by the root cap
Root cap
cells that must be replaced constantly because the get ground off by rough soil particles as the root grows
Cortex
large, thin-walled parenchyma cells; next to the epidermis; irregularly-shaped, loosely packed, making it possible for water and minerals to move through the cortex without entering the cells; contain starch granules; function = food storage
Endodermis
single layer of rectangular cells that forms a boundary between the cortex and the inner vascular cylinder
Casparian strip
impermeable lignin and suberin that borders the endodermal cells on 4 sides; prevents the passage of water and mineral ions between adjacent cell walls; regulates entrance of minerals into the vascular cylinder
Pericycle
1st layer of cells within the vascular cylinder; capacity to divide and can start the development of branch, or lateral, roots
Pith
ground tissue of a monocot’s root this is centrally located and surrounded by a vascular ring composed of alternating xylem and phloem bundles
Primary root
in some plants, notably dicots, the 1st or this root, grows straight down and remains the dominant root of the plant
Taproot
dominant root of the plant; often fleshy, stores food; carrots, beets, turnips, and radishes have these that we consume as vegetables
Fibrous Root System
in monocots, there is no single, main root; instead, a large number of slender roots grow from the lower nodes of the stem when the 1st/primary root dies; these slender roots and their lateral branches make up this; most grasses have this
Adventitious roots
when roots develop from organs of the shoot system instead of the root system; typically found in corn plants (prop roots)
Root nodules
peas, beans, and other legumes have these where nitrogen-fixing bacteria live
Terminal bud
part of the stem that contains the shoot tip protected by modified leaves called bud scales
Shoot apical meristem
protected within the terminal bud, where leaf primordia (immature leaves) envelop it
Protoderm
outermost primary meristem; gives rise to the epidermis
Ground meristem
produces 2 tissues composed of parenchyma cells (pith and cortex)
Procambium
produces the 1st xylem cells, called primary xylem, and the 1st phloem cells, called primary phloem
Vascular cambium
mature vascular bundles contain fully differentiated xylem, phloem, and a lateral meristem called this
Herbaceous stems
mature nonwoody stems; exhibit only primary growth
Bark
part of a tree that contains periderm (cork and cork cambium) and phloem
Wood
secondary xylem that builds up year after year, thereby increasing the girth of trees
Annual ring
when the trunk of a tree has spring wood followed by summer wood, the 2 together make up one year’s growth, called this; you can tell the age of a tree by counting these
Stolons
aboveground horizontal stems; AKA runners; produce new plants where nodes touch the ground
Rhizomes
underground horizontal stems; may be long and thin (as in sod-forming grasses) or thick and fleshy (as in irises); survive the winter and contribute to asexual reproduction because each node bears a bud
Corms
bulbous underground stems that lie dormant during the winter; produce new plants the next growing season
Mesophyll
body of a leaf is composed of this type of tissue
Palisade mesophyll
1 of 2 distinct regions of a dicot leaf containing elongated cells
Spongy mesophyll
2nd of 2 distinct regions of a dicot leaf containing irregular cells bounded by air spaces
