Glossary Entries




From W-CHROMOSOME To ZYGOSPORE   


Start at :- X, Y, Z, Go to End of Page


Name Origin Description Extra
W
W-CHROMOSOME
n [Gk. chroma, colour; soms, body]
A sex determining chromosome in some animals like birds and moths. The distribution of the sex chromosomes is different than normal - males have two Z chromosomes, and females have one Z and one W. Normally in mammals, males have an X and Y sex chromosome and females have two X sex determining chromosomes, but male birds or moths have two Z chromosome pairs and females have one Z and one W chromosome. The Y and the W chromosomes are smaller and the X and Z are larger. Therefore in birds or moths there is an opposite mirror image in the sex determining chromosomes where the female is the heterogametic sex.
WATER POTENTIAL(WP)
n [O.E. waeter, water; L. potentia, power]
The capacity of tissues or soil to hold or absorb water. It is the energy level of water relative to pure water.
WATER SHOOTS
n [O.E. waeter, water; sceota, shot]
Applied usually to epicormic shoots that frequently arise close to pruning wounds on tree trunks or branches.
Water soaked
n [ O.E. waeter, water; sucan, to suck]
Is a symptom of diseased plant tissues, usually of bacteria or fungi attack, where the tissues looks wet or translutant.
WHIP
n [M.Du. wippen, swing]
A young seedling or grafred tree without lateral branches.
WHIP GRAFTING
a [M.Du. wippen; O.Fr. graffe, graft]
Whip grafting, tongue grafting, the same as splice grafting, except that a cleft or slit is made in the end of both scion and stock, in the direction of the grain and in the middle of the sloping surface, forming a kind of tongue, so that when put together, the tongue of each is inserted in the slit of the other. See GRAFTING.
WHIP-AND-TONGUE GRAFTING
a [M.Du. wippen, swing; O.E. tung, tongue; O.Fr. graffe,graft]
Whip and tongue grafting is used for the production of fruit stock and some ornamentals. It is normally undertaken in March or early April on rootstocks planted 12 months previously. This technique uses two cuts on both the scion and the rootstock, which enables the two parts to be 'locked' together. This gives a structurally strong graft suitable for field conditions. See GRAFTING.
WHORL
n [A.S. hweorfan, to turn]
The arrangement of three or more organs, such as leaves, petals, sepals and stamens arising from the same level in an encircling ring. Image /leafshapes/38?gloss=1&ordr=0&telephone=7
WIDGER
n [Engl. from 1950's]
A spatula-shaped tool, used for transplanting or pricking out seedlings.
WILT
v [Ger. welk, lose freshness]
the lack of turgor pressure in plants cells leading to drooping.
WIND-ROCK
n [O.E. windan, go rapidily; roccian, remove]
The destabilizing of a plant's roots by strong wind.
WINDBREAK
n [O.E. windan, go rapidly; brecan, brake]
Any structure but often a hedge, fence, or wall that shelters plants and filters strong winds.
WING PAD
n [O.N. vaengir, wing;Ger. pad, sole of the foot]
The undeveloped wing of nymphal insects.
WINGED
a [O.N. voengir, to play a role]
Having wide, flat edges. Winged petioles usually have two such edges winged stems usually have four.
WINTER WET
n [O.E. woet, to water]
Excessive amounts of water that accumulate in the soil during the winter months.
WITCHES BROOM
n [O.E. wicca, female; brom, brushwood]
An abnormal growth of branches from one place in many trees and plants as a result of attack by fungi, insects, bacteria or viruses.
WOODY
n [A.S. wudu, wood]
Ligneous, a term describing stems or trunks that are hard ant thickened rather than soft and pliable. (Cf. HERBACEOUS.)
WOUND
n [O.E. wund, injury]
A cut or broken area in a plant.
WOUND PAINT
n [O.E. wund, injury; L. pingere, to paint]
A specialized paint that used to be applied to a cut plant after pruning.
X
X-CHROMOSOME
n [Gk. chroma, colour; soms, body]
One of the two sex determining chromosome, in most mamals, which pairs with the Y-CHROMOSOME in hetrogametic sex. Females do not have a Y chromosome. The DNA in the Y chromosome is passed from father to son.
XEROMORPHIC
n [Gk. xeros, dry; morphe, form]
Possessing characteristics such as reduced leaves, succulence, dense hairiness or a thick cuticle which are adaptations to conserve water and so withstand extremely dry conditions.
XEROPHYTE
n [Gk. xeros, dry; phyton, plant]
A plant which is adapted to withstand extremely dry conditions.
XYLEM
n [Gk.xylon, wood]
The woody fluid-conveying (vascular) tissue concerned with the transport of water about the plant. cf. PHLOEM VESSEL.
Y
Y-CHROMOSOME
n [Gk. chroma, colour; soms, body]
One of the two sex determining chromosome, in most mamals, which pairs with the X-CHROMOSOME in hetrogametic sex. Females do not have a Y chromosome. The DNA in the Y chromosome is passed from father to son
YELLOWS
n [O.E. geolu, rel. to gold]
Yellows is a plant diseases that causes yellowing of the leaves and stunted growth. In diseased plants there are many membrane-bound structures resembling mycoplasma-like organisms within the phloem sieve elements although these are not confirmed as the agents of the disease. Some of the yellows agents could be obligate intra-cellular parasites.
Z
Z-CHROMOSOME
n [Gk. chroma, colour; soms, body]
A sex determining chromosome in some animals like birds and moths. The distribution of the sex chromosomes is different than normal - males have two Z chromosomes, and females have one Z and one W. Normally in mammals, males have an X and Y sex chromosome and females have two X sex determining chromosomes, but male birds or moths have two Z chromosome pairs and females have one Z and one W chromosome. The Y and the W chromosomes are smaller and the X and Z are larger. Therefore in birds or moths there is an opposite mirror image in the sex determining chromosomes where the female is the heterogametic sex.
ZONAL
a [L. zonalis, pert. to zone ]
Pertaining to a zone.
ZONATE
a [L. zona, girdle]
Zoned or marked in concentric lines. Often forming pale and darker zones.
ZOOLITE
n [Gk. zoon, animal; lithos, stone]
A fossil animal. alt[ZOOLITH]
ZOOLITH
n [Gk. zoon, animal; lithos, stone]
A fossil animal. alt[ZOOLITE]
ZOOLOGY
n [Gk. zoon, animallogos, discource]
The science of all aspects like form, function, behaviour, distribution and history of animals.
ZOON
n [Gk. zoon, animal]
an individual animal developed from an egg
ZOOSPORANGIUM
n [Gk. zoon, animal;sporos, seed; anggeion, vessel]
A vessel in which zoospores are formed.
ZOOSPORE
n [Gk. zoon, animal; sporos, seed]
A flagella bearing motile cell for sexual reproduction in algae and fungi.
ZYGOSPERM
n [Gk. zygon, yolk; sporos, seed]
The resting spore of zygomycetes formed by the conjugation of similar sex cells. alt[ZYGOSPORE].
ZYGOSPHERE
n [Gk. zygon, yolk; sphaira, globe]
A gamete that conjugates with a similar gamete forming a zygosphore.
ZYGOSPORE
n [Gk. zygon, yolk; sporos, seed]
The resting spore of zygomycetes formed by the conjugation of similar sex cells. alt[ZYGOSPERM].

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