Download Plant Structure 2 Root that does not develop from the radicle, e.g. (a

Plant Structure 2
Root that does not develop from the radicle, e.g. (a) climbing roots
of ivy, (b) roots of cuttings that arise from a node.
adventitious root
Bud found at the apex or tip of a shoot.
apical bud
Meristem (embryonic tissue) found at tip of shoot or root
responsible for increasing the length of the shoot or root.
apical meristem
A bud found in the axil of the leaf, i.e. in the angle between the
petiole of the leaf and the stem.
axillary bud
The ability of water to climb in tubes of narrow bore (xylem) or
between tightly packed particles due to its adhesive and cohesive
properties, e.g. in the spaces between soil particles.
capillarity
Force with which molecules of the same substance stick to each
other.
cohesive
Modified stem – short, vertical, swollen. Terminal bud produces
leaves and flowers above ground. New corm formed on top of old,
e.g. crocus, gladioli.
corm
A ‘seed leaf’, i.e. the first leaf that develops in the embryo. It is a
food store.
cotyledon
Plant that sheds its leaves and has a period of dormancy annually,
e.g. oak, ash, etc.
deciduous
Who put forward the most acceptable theory of water movement
through a plant? Based on cohesive forces of water, i.e. the force
of attraction between water molecules is great enough to maintain
a continuous column of water.
Water in the soil that can be absorbed into roots of plants by
osmosis. Due to the adhesive forces of water molecules some soil
water is not available, i.e. the root hairs cannot exert enough
osmotic pressure to pull the water off the soil particles.
Refers to a plant that does not develop persistent woody tissues
(xylem), i.e. has a non-woody stem. Aerial parts of these plants
usually die in winter.
The part of a stem between two nodes.
Dixon and Joly
free water: available
(soil) water
herbaceous
internode
Roots arising from the side and growing horizontally away from the
lateral root(s)
main vertical tap root.
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Outgrowth from stem which functions in photosynthesis,
transpiration and respiration. Size can vary from large and flat to
needle-like.
leaf
Strengthening material found impregnated in cellulose cell walls of
woody tissue.
lignin
Layer of loosely packed chlorophyll-containing cells in lower half of
leaf, above the lower epidermis.
mesophyll
Root that has undergone changes in structure in order to adapt to
its environment, store food and survive adverse conditions, e.g.
root tuber.
Refers to plants that are herbaceous, have embryo/seed with one
seed leaf, flower parts in units of three, leaves with parallel veins
and a stem with scattered vascular bundles, and fibrous roots, e.g.
grasses.
modified root
monocotyledon(ous)
An interlacing complex system of veins in a leaf. Typical of
dicotyledonous lea
netted venation
Refers to any plant that does not have vascular tissue (xylem), e.g.
moss.
non-vascular
A system of veins in a leaf where the veins run in parallel lines and
are all more or less the same length. Typical of monocotyledonous
plants.
parallel venation
The stalk or stem of a leaf, supporting the leaf blade.
petiole(s)
Long cells, thin side walls, thick perforated end walls allow passage
of cytoplasm between cells. No nucleus when mature.
phloem sieve tube
Basic unit of which all plants are composed, differs from animal
cell in that it has a cell wall.
plant cell
Main tap root or most important root.
primary root
The tips of a flower stalk on or around which the flower parts
develop.
receptacle
The part of a plant that grows downwards into the soil. It functions
in anchorage, absorption and sometimes storage. They do not
have leaves or buds. They take in mineral salts by active transport.
They absorb water by osmosis.
Tubular, hair-like extension of certain epidermal root cells. Found
just behind apical meristem. Function is to increase surface area
for absorption of water and soluble minerals.
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root
root hair
Swollen fibrous roots, no eyes (buds), e.g. dahlia, lesser celandine.
root tuber
Refers to a type of leaf with no stalk or petiole i.e. the leaf is
attached directly to the stem, e.g. moss, sessile oak.
sessile
Elongated cells in phloem tissue, placed end to end and separated
by a perforated cell plate so that the cytoplasm of one cell is
continuous with the cytoplasm of the adjoining cell.
sieve tube cell
Swollen underground stem tip. Buds (eyes) produce new shoots,
e.g. potato.
stem tuber
Horizontal outgrowth from plant running under the soil surface –
terminal bud sends up new shoot, e.g. raspberry.
sucker(s)
A slender, thread-like structure of some climbing plants that curls
around objects and helps support the plant, e.g. pea, sweet pea,
vetch, etc.
tendril
Seed coat. Outer covering of seed formed from integuments.
testa
The flow of water through a plant, from root hair cells to stomatal
openings in leaves, as a result of the loss of water by transpiration.
transpiration stream
A longitudinal strand of conducting tissue made up of xylem,
phloem and sometimes cambium.
vascular bundle
Refers to the group of cells with a similar function involved in the
transport of substances, i.e. xylem and phloem in plants, and blood vascular tissue
in animals.
Water in a gaseous form suspended in the air.
Long, relatively narrow, dead cells, containing lignin for support.
Tapered at both ends, pits in the walls to allow sideways
movement from cell to cell of water and minerals.
Area in root and shoot tips where simple cells become modified
and specialised to perform specific tasks (e.g. xylem, phloem, etc.)
depending on where they are located.
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water vapour
xylem tracheids
zone of
differentiation