### substance | gall:

Aerial gall
* are common on such highly susceptible plants as poplar, rose, willow, and euonymus.
* can develop but most are found at or just below the soil line.

### substance | gall:

Crown gall
* are tumorous growths due to increased stimulation of cell division and enlargement.
* attacks the vines near soil level.
* bacterialdisease caused by Agrobacterium tumefaciens.
* causes formation of roundish galls with irregular rough surfaces.
* develop in the spring on the underground parts, the roots and crown, of the plants.
* differ from natural burls.
* difficult disease to control once a plant is infected.
* disease caused by a bacterial patho-gen, Agrobacterium tumefaciens
  - of apples and other members of the rose family
* is actually a tumor, bacterial in nature.
* is caused by Agrobacterium and related bacteria
  - a bacterium that survives in the soil
  - the soil-inhabiting bacterium Agrobacterium tumefaciens
  - characterized by galls or overgrowths that usually form at the base of the trunk
  - controlled through preventive cultural and sanitation practices
* is most damaging to young trees, either in the nursery or in new plantings
  - either in the nursery or new orchard plantings
  - recognized by the presence of rough galls or over growth on the roots, crown or canes
* occurs as tumorous rough surface growths on roots and crowns of trees.
* plant disease
* refers to the formation of tumors on roots and crown of many dicots.
* tumorous growth of tissue up to several inches or more in diameter.

Large gall
* can develop rapidly and completely girdle a young vine in one season.
* minimize larval parasitism which is high in Europe.

Old gall
* are a dark brown and usually have an exit hole.
* are reddish-brown and have open cavities
  - several small, open cavities
* have a ridged and furrowed surface, are hard, and grayish in color.

Gaseous substance
* All gaseous substances are said to have gaseous state.
* are in a league all to themselves.

Gem material
* exhibit characteristic refractive indexes which vary from species to species.
* vary in the quality of the light they can refract.

Genetic material
* Some genetic material is saved as seed or as tissue culture plants.
* are an increasing force in today's international livestock commerce.
* can link a defendant to a crime.
* influences the ability to adapt.
* inserted into plants can transfer to animals and humans in the intestinal wall.
* is contained on chromosomes
  - introduced into the host cells chromosomes
  - randomly mixed during fertilisation

### substance:

Gibberellin
* also stimulate alpha amylase synthesis is the aleurone layer in cereal grains.
* are a second class of hormones that stimulate plant growth
  - diterpenoids derived from four isoprenoid units forming a system of four rings
  - growth-promoting hormones
  - hormones that are found throughout the plant
  - most important in stems, fruits and seeds
  - natural plant hormones
* are plant hormone that is in charge of stem elongation
  - hormones which affect stem height and, in many species, promote germination
  - the leaves and roots that form in the baby plant seed
  - used in agriculture for various purposes
  - well known to promote uniform growth through cell enlargement
* cause enzymatic activity.
* generally have no influence on plants of normal size.
* growth regulator
* have many different effects on plants
  - several effects in green plants, such as cell and stem elongation
* promote stem elongation between nodes on the stem.
* regulate growth, flowering and germination.
* stimulate cell division and elongation but act more slowly than auxins
  - growth in plants

Gneiss
* Some gneisses are used as facing stone on buildings
  - have pressure
* are heterogeneous - banded
  - very coarse grained metamorphic rocks that form during high grade metamorphism
* resemble schists in that both are banded and show foliation.