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Home >>Botany Dictionary >> Eumitosis - Eyespot
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Eumitosis - A normal mitosis, in which the chromosomes separate distinctly, and clearly divide longitudinally.
Euphilic - Said of flowers of an insect pollinated species that can be pollinated by a specific insect only.
Euploidy - Used for describing the condition where organism possesses such a number of chromosomes in its nuclei that is an exact multiple of the haploid number.
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Eusporangium - Used for the sporangikum that is derived from a number of sporangial initials. It is typical of ferns in Marattiales and Ophioglossales.
Eustele - Describing a type of dissected siphonostele ( typicall of dicotyledons) in which vascular cylinder appears as a ring of collateral (or bicollateral) bundles separated by medullary rays in transverse section.
Eutrophic - Used for the condition of richness of minerals and bases. This term is generally used to describe nutrient rich lakes an ponds. Ever Bearer, Ever Bloomer. A plant producing leaves and flowers for a long period of the growing season, and often, bearing flowers and fruits at the same time.
Evergreen - Used for a woody perennial plant that is bearing and losing leaves continuously throughout the year.
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Exarch - Used for a xylem strand which has the protoxylem farthest from the centre of the axis.
Exasperate - Having a hard, roughened surface, with short point projecting from it.
Exine - The outer portion of the wall of a pollen grain which is external to intine, It is composed of carotenoid polymer sporopollenin which is highly resistant to decay.
Exocarp (epicarp, ectocarp). Describing the outmost layer of pericarp of an angiospermic fruit which is lying external to mesocarp, usually a thin layer only forming the outermost skin of fruit.
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Exodermis - Describing a layer of cells in certain plants, often lying immediately beneath the epidermis or velamen of root. It is essentially a specialized hypodermis.
Exogenous - Used for any process .or substance having its origin outside the organism or the organ arising from the peripheral layers of the body of the organism.
Exon - Describing a polynucleotide sequence that can code for a specific protein.
Exoskeleton - A hard supportive and protective external covering on the body of an organism such as the deposition of calcium carbonate on certain algal members of Charophyta and Rhodophyta.
Exotic - Used for an organism in an area which is not a native of the area but has its origin in some other region. 1f a plant becomes adapted to its new environment, it is said to be naturalized.
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Exosscopic Embryogeny - The pattern of embryo development in which embryo proper develops from the outer one of the two cells formed after first division of zygote whereas the inner cell forms the foot. It is observed in Bryophyta, Psilopsida and Sphenopsida.
Exosmosis - Exit of water or solvent by the process of osmosis from a solution which is bounded by a semipermeable membrane to the exterior; e.g., the loss of water by a living cell due to osmosis.
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Exotoxin - Used for toxic substances which are produced in the cells of many Gram positive bacteria and immediately released through bacterial wall into the surroundings.
Explanation - Used for the removal of parts of the body of a living organism for culture in a suitable artificial medium. Such revoved part is called explantand often consists of only small segment of tissue e.g., leaf discs or meristems. Placements of explants in to or onto the culture medium is called inoculation.
Exponential Growth - Used for describing growth of a population in which rate of increase of numbers is proportional to the number of members already present. Graph of number of members against time has the shape of exponential curve (i.e., J-shaped).
Extracellular: Describing a process or substance that is located outside the cell.
Extrachromosomal Inheritance - See cytoplasmic inheritance.
Extrafloral Nectary - Used for nectary which is situated outside the flower or at any place other than inside of flower e.g., gland spines of certain cacti where they attract seed dispersal agents such as ants.
Extrastellar Cambium - Used for the cambium which is formed outside the stele i.e., not from intra and interfascicular cambia. It may be formed in pariccyclic regionor in the ground tissue.
Extrorse - Used for an thers that dehisce and release pollens towards periphery of flower i.e., to the outside of flower.
Exudation - The liberation of liquid water, or sap from special pores on the plant.
Eyespot - A light-sensitive organelle found in some of the moti1green algae. It consists of a pigment-cup, covered by a light sensitive substance, and sometime with a lens external to this.
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