light reaction n. The first step in the process of photosynthesis, which begins when the chlorophyll molecule absorbs a photon; light is required.
lignin n. An important constituent of many secondary cell walls that increases the cell wall’s hardness and strength.
lipid n. A category of organic macromolecules including fats and oils.
long-day adj. Describes plants that initiate flowers when day length is longer than their critical day length.
M macrofibril n. A structure made up of several microfibrils wound together into a "cable;" provide the framework for the plant cell wall.
macromolecules n. Relatively large molecules made up of smaller molecules bound together with chemical bonds.
macronutrients n. The mineral nutrients that plants require in relatively large quantities; includes carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
megaspore n. Haploid cells formed by meiosis in plants; divide by mitosis to form several daughter cells, one of which functions as the egg cell.
meiosis n. Cell division that results in four haploid daughter cells.
meristem n. A region of actively-dividing cells.
mesophyll n. The tissue sandwiched between the epidermal layers of a leaf; containing both the palisade cells and the spongy cells.
metabolic adj. The chemical processes occurring within a living cell or organism.
microbe n. A minute organism.
microfibril n. A structure made up of several cellulose molecules united into a thread-like strand.
micronutrients n. The mineral nutrients that plants require in relatively small quantities includes magnesium, iron, copper, zinc, manganese, molybdenum, and boron.
micropyle n. The opening in the ovule where the pollen tube enters.
microspore Haploid cells formed by meiosis in plants; divide by mitosis to form pollen—precursor to the sperm cell.
middle lamella n. A pectin-rich layer between adjoining plant cell walls, cementing them together.
mitochondria n. A double-membrane-bounded organelle found in eukaryotic cells.
mitosis n. Cell division that results in two daughter cells that are genetically identical to the parent cell.
molecule n. The smallest unit of a compound; consists of two or more different atoms in a specific ratio and configuration, held together with chemical bonds.
monocot n. A class of angiosperms in which the seeds’ cotyledons occur singly.
monoecious adj. Describes plants with separate male and female flowers.
monosaccharide n. A simple sugar made up of a chain or ring of carbon atoms to which hydrogen and oxygen atoms are attached.
mordant n. A chemical agent that fixes dye to fabric.
multiple fruit n. The fruit that results from the fusion of the ovaries of flowers that are growing very close to one another on a shared flower stalk.
mutation n. A random genetic variation that is passed on to offspring.
mutualism n. Relationship of two or more organisms in which both organisms benefit.
N nastic movement n. Movement of plant parts not associated with a specific stimulus such as light or gravity.
natural selection n. A process by which the healthiest, strongest, and most well-adapted organisms flourish and reproduce.
nodes n. Sites on a stem where the leaves and axillary buds are attached.
non-native plant n. A plant that has been introduced-either intentionally or accidentally-into an area in which it was not found previously.
nucleus n. A structure within a plant cell; controls cell functions, including inheritance.
O order n. A group of families sharing similar characteristics.
organelle n. A membrane-bound part of the cell that has a specialized function.
organic adj. Refers to substances containing carbon; pertaining to living organisms.
osmosis n. The movement of water across a differentially permeable membane, from a place where water concentration is higher to one where the concentration is lower.
ovary n. A female reproductive structure, containing ovules, usually found at the basal portion of the flower. After pollination, the ovary matures into a fruit; the ovules develop into seeds.
ovule n. A female reproductive structure which, upon fertilization, develops into a seed.
oxidative phosphorylation n. The last stage of respiration, during which ATP (adenosine triphosphate) is formed from ADP (adenosine diphosphate).
P palisade cells n. A layer of closely-packed, elongated cells located just beneath the upper epidermis of a leaf. These cells contain chloroplasts, and are the main sites of photosynthesis.
parasite n. An organism that derives some or all its nutrients from another organism.
pathogen n. A disease-causing organism.
pectin n. A gluey substance found in the middle lamella between adjoining cell walls that cements the adjoining cells together.
perennial adj. Describes a plant that lives for more than two years; commonly used to describe herbaceous (non-woody) plants.
perfect adj. This term describes a flower that has both male and female reproductive structures.
petiole n. The stalk or support that attaches the blade of a leaf to the stem.
phloem n. The food-conducting tissues of plants; part of the vascular system.
photoperiodism n. The initiation of flowering based on the relative amounts of darkness and light in a 24-hour period.
photosynthesis n. The process by which plants use light energy to manufacture sugars.
phototropism n. The bending of a plant organ in response to light.
phytochrome n. A light-sensitive protein pigment involved inthe photoperiodic response.
pigment n. A substance that absorbs light.
pistil n. The female reproductive structure.
plant growth regulators n. Chemical messengers within the plant body that control growth.
plastids n. Structures found in plant cells; often contain pigments.
pollen tube n. A long, hollow tube formed by the pollen grain's tube cell that penetrates the pistil's tissues to reach the egg cell.
pollination n. The successful transfer of pollen from the anther to a receptive stigma.
pollinator n. Any organism responsible for transferring pollen to stigma of flowers, including bees and other insects, small rodents, and bats. Many plants require a specific pollinator.
polyploid adj. Used to describe a nucleus with more than two complete sets of chromosomes.
polysaccharide n. A carbohydrate composed of many monosaccharide units bound together in a long chain; examples include cellulose and starch.
pome n. A simple, fleshy fruit. Examples include pears and apples.
poultice n. Moistened herbs applied directly to the skin and held in place with a bandage.
primary growth n. Growth arising from cell division and elongation in the regions of apical meristems.
primary wall n. The initial layer of a plant cell wall.
producer n. An organism that manufactures complex organic molecules from simple inorganic substances. In most ecosystems, producers are photosynthetic organisms.
protein n. A category of organic macromolecules composed of many amino acids chemically bound together.
R ray flowers n. The flowers that surround the disk flowers in the inflorescence of plants in the Daisy family.
recessive trait n. A characteristic whose expression is masked by the presence of the comparable dominant gene; this characteristic will be expressed only if both genes are recessive.
replication n. The exact duplication of the genetic material within a cell.
reproductive cells n. Haploid cells (egg and sperm), the fusion of which results in the creation of a new organism. Also called gametes or sex cells.
respiration n. The process of breaking chemical bonds in carbohydrates to release the energy necessary to perform metabolic functions.
rhizobium n. Bacteria that form a symbiotic relationship with plants in the legume family, resulting in the ability of the members of this family to fix atmospheric nitrogen.
rhizome n. Horizontal underground stem; may be fleshy or not. Used for food storage and asexual propagation.
roots n. The plant part generally found underground; responsible for anchoring the plant as well as water and nutrient uptake.
rosette n. Aboveground vegetative growth that is present in certain species before flowering in which the leaves are present but the internodes between them are not elongated.
S n. An organism that fills its nutritional needs from dead and decaying organic matter.
scarification n. Abrading or softening of the seed coat to encourage germination.
n. Growth arising from cell division and elongation in the regions of lateral meristems.
n. A second layer of cell wall laid down by the protoplast inside the primary wall.
n. The fertilized and matured ovule of a flowering plant, containing an embryonic plant, and which, on being placed under favorable circumstances, develops into an individual similar to the one that produced it.
n. The hard, protective coating covering a seed.
n. A category of evolutionarily primitive plants that do not form seeds. Includes mosses and ferns.
n. In mosses, the tall, stem-like structures on which spore capsules are borne.
n. The creation of offspring from the union of egg and sperm.
n. The aboveground portion of a plant, consisting of the stem and leaves.
adj. Describes plants that initiate flowers when day length is shorter than their critical day length.
simple fruit n. The fruit that develops from a single pistil on a single flower.
simple leaf n. An undivided leaf that has only a single blade.
sister chromatids n. Genetic material composed of one original chromosome and one exact duplicate produced during replication.
n. Diploid cells that make up the bulk of the plant body; all cells in a plant that are not reproductive cells.
n. The "specific" name of a plant; used to describe a plant within a genus.
n. The degree to which two organisms must be compatible before a relationship will form.
n. A layer of loosely-packed cells located beneath the palisade cells of a leaf. The spaces between the cells allow for the exchange of gases necessary for photosynthesis.
n. The product of meiosis in plants; germinates to form the gametophyte generation.
sporophyte generation n. The phase of growth in which spores are formed.
n. A carbohydrate composed of several hundred glucose units; the chief food storage substance in plants.
stamen n. The male reproductive structure in the flower-composed of the anther and the filament-where pollen produced.
n. The leaf- and flower-bearing part of a plant.
stem nodes n. The location on the stem where branches or leaves are attached.
stigma n. The sticky surface of the stigma where pollen is received and on which pollen germinates.
n. Small, leaf-like outgrowth found at the base of a leaf stalk.
n. Horizontal creeping aboveground stem; sprouts new plants at nodes.
n. Tiny pores in the epidermal cells of leaves and stems; most numerous on the undersides of leaves. (Singular: stoma or stomate. Plural: stomata or stomates).
stratification n. Exposure of seeds to cool temperatures to break dormancy and encourage germination.
stroma n. The structure within the chloroplast where the dark reactions of photosynthesis take place.
style n. The column of tissue that stretches from the ovary to the stigma through which the pollen tube grows.
succession n. The sequence of changes in the vegetative composition of a community from initial colonization to climax.
n. Shoot arising from adventitious bud on underground root; sometimes used to describe any shoots arising at the base of a plant.
n. Relationship of two or more organisms living in close association.
T n. A root system consisting of one or more prominent, swollen roots with few side roots; often a food-storage structure.
taxonomist n. A scientist who specializes in the classification of organisms.
terrarium n. An enclosure for raising plants or animals indoors.
n. The reaction of a plant in response to physical contact.
thylakoid n. The structure within the chloroplast where the light reactions of photosynthesis take place.
n. Propagation method that produces many plants from one or a few initial cells. Must be done under sterile, controlled conditions.
trait n. An inherited physical or physiological characteristic.
transgenic adj. Organisms created using genetic engineering.
transpiration n. The loss of water vapor from a plant; most of this water escapes from open stomata.
triploid adj. Describes a plant cell in which the chromosomes occur in three’s.
tube cell n. One of two cells that make up a pollen grain; upon successful pollination, it germinates and grows into the pollen tube.
tuber n. Swollen tip of an underground stem, used for food storage and asexual propagation.
tuberous root n. Enlarged secondary root, used for food storage and asexual propagation.
tuberous stem n. Swollen section on underground portion of main stem, used for food storage and asexual propagation.
turgor pressure n. The pressure within a plant cell; maintained by osmosis.
V variegated adj. Describes leaves or petals exhibiting an irregular, inherited pattern of color.
variety n. A population within a species that differs from other members of the species in some significant way. Written in italics after the species name.
vascular cambium n. A type of lateral meristem that gives rise to new xylem (wood) and phloem (inner bark).
vascular tissues n. Food- or water-conducting tissues.
vermiculture n. Worm composting.
vernalization n. The promotion of flowering due to exposure to low temperatures, or chilling.
W whorl n. A circle of flower parts of one kind. Most flowers are composed of four whorls: petals, sepals, stamen, and pistil.
X xylem n. The water-conducting tissues of plants; part of the vascular system.
Z zygote n. The cell created by the union of egg and sperm; divides to become the embryo
منبع: www.ake.blogfa.com منبع: www.ake.blogfa.com منبع: www.ake.blogfa.com