ศัพท์และความหมายเกี่ยวกับเฟิน

A Glossary of Terms from Lab 7
adventitious roots
Roots that have differentiated from the kinds of tissue other than root tissue.

annulus
The ring of cells in the moss or fern capsule that splits and allows liberation of spores.

anther
The terminal pollen sac of a stamen, inside which pollen grains with male gametes form in the flower of an angiosperm.

antheridium (pl. antheridia)
The male sex organ or gametangium, within which male gametes are formed, in algae, fungi, bryophytes (mosses, liverworts, etc.), and pteridophytes (ferns).

archegonium (pl. archegonia)
The female sex organ or gametangium of liverworts, mosses, ferns, and most gymnosperms. It is usually a flask-shaped organ, comprising a swollen base or venter containing a single egg-cell and a slender elongated neck containing one or more layers of cells.

cuticle
(1) a waxy covering on the surface of stems and leaves that acts as an adaptation to prevent desiccation in terrestrial plants. (2) the exoskeleton of an arthropod, consisting of layers of protein and chitin that are variously modified for different functions.

dioecious
Possesses male and female flowers or other reproductive organs on separate, unisexual, individual plants.

frond
A big compound leaf applied to those of palms and ferns.

gametangium (pl. gametangia)
The reproductive organ of bryophytes, consisting of the male antheridium and female archegonium; a multichambered jacket of sterile cells in which gametes are formed.

gametophyte
The part of the life cycle of plants having haploid nuclei and giving rise to the sex cells that on fusing produce a diploid stage, usually the sporophyte.

homospory
The possession of only one form of spore. This gives rise to a single gametophyte generation carrying both male and female reproductive organs.

lateral (secondary) roots
The branches that develop from deep inside the plant root. This type of branching is initiated by the plant hormone, auxin.

leaf
A thin organ arising from the node on the stem of a plant. The main site of phtosynthesis.

liverworts
Belong to the class Bryophyta and are found in damp and wet conditions.

mesophyll
The ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis.

monoecious
Referring to a plant species that has both staminate and carpellate flowers on the same individual.

moss
Any bryophyte of the class Musci. Usually these are small plants (less than 5 cm high) attached to moist or wet substrates by rhizoids; this is the sporophyte generation. The sexual organs are borne on a gametophyte generation, and the antheridia and archegonia are on separate leaf rosettes.

parenchyma cells
a relatively unspecialized plant cell type that carries on most of the metabolism synthesizes and stores organic products, and develops into more differentiated cell types.

phloem
The portion of the vascular system in plants consisting of living cells arranged into elongated tubes that transport sugar and other organic nutrients throughout the plant.

primary root
The first root of the plant. It develops in continuation from the root tip.

rhizoid
A hair-like structure that functions as a root in lower organisms, such as certain fungi and mosses. Rhizoids are important in penetrating a substance, giving anchorage and absorbing nutrients.

rhizome
A horizontal underground stem, with leaves and buds, that serves as a storage organ and a means of vegetative propagation.

root
The part of a plant that usually grows below ground. The root provides anchorage for aerial parts, absorbs water and mineral salts from the soil, conducts water and nutrients to other parts of the plant, and often stores food materials over winter.

seta (plural, setae)
1. the erect aerial part of the spore-producing structure of mosses or liverworts. 2. a slender, straight prickle.

sorus (pl. sori)
A group of sporangia developed on the underside of sporophylls (spore-bearing leaflets) of the sporophyte generation of a fern.

sporangium (pl. sporangia)
A capsule in fungi and plants in which meiosis occurs and haploid spores develop.

sporophyte
The multicellular diploid form in organisms undergoing alternation of generations that results from a union of gametes and that meiotically produces haploid spores that grow into the gametophyte generation.

stem
The part of the plant bearing the buds, leaves, and flowers. It forms the central axis of the plant, and provides mechanical support. If present below ground, it is usually called a rhizome.

stoma (pl. stomata)
A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant.

thallus
The vegetative part of simple plants, ranging from unicellular structures to large seaweeds. It shows no differentiation into root, stem, and leaves.

venter
The swollen base of the archegonium that contains the egg cell.

xylem
The tube-shaped, nonliving portion of the vascular system in plants that carries water and minerals from the roots to the rest of the plant.

zygote
The diploid product of the union of haploid gametes in conception; a fertilized egg.