Gallbladder

The saclike organ in vertebrates that is connected to the liver that stores bile.


Gametangium

In algae and fungi, a gamete chamber.


Gamete

A reproductive cell.


Gametocyte

An undifferentiated cell that develops into a gamete.


Gametophyte

In plants and algae, a multicellular structure that produces gametes.


GanglionA mass of nerve cells.

Gasohol

An alternative fuel made from alcohol from fermented grains mixed with gasoline.


Gastric Cecum

A pocket that branches from the digestive tract and secretes enzymes.


Gastric Fluid

A liquid secreted by gastric glands in the stomach.


Gastric Pit

The open end of gastric glands through which secretions are released into the stomach.


Gastrin

A hormone that stimulates the stomach to secrete digestive enzymes.


Gastrodermis

In cnidarians, the layer of cells surrounding the gastrovascular cavity.


Gastrointestinal Tract

The digestive tract from the mouth to the anus.


Gastropod

A mollusk that has one or no shell and moves by gliding on a muscular foot; examples include snails, slugs, and nudibranchs.


Gastrovascular Cavity

A digestive chamber with a single opening found in cnidarians, ctenophores, and flatworms.


Gastrula

The cup-shaped embryo formed as the blastula folds inward.


Gel Electrophoresis

Technique used to separate nucleic acids or proteins by size and charge.


Gemmule

An asexual reproductive structure produced by some freshwater sponges.


Gene

A segment of DNA that contains coding for a polypeptide or protein; a unit of hereditary information.


Gene Clone

An exact copy of a gene.


Gene Expression

The transcription of DNA into RNA and then into proteins.


Gene Flow

The movement of genes into or out of a population.


Gene Pool

All the genes for all of the traits in a population.


Gene pool

The sum total of all the genes that exist among all the individuals of a species.


Gene Therapy

Treatment of a genetic disorder by introducing a healthy gene into a cell.


Generalist

A species with a broad niche that can tolerate a wide range of conditions and can use a variety of resources.


Generative Cell

In a pollen grain, the cell that forms two sperm.


Genetic Code

Triplets of nucleotides in mRNA that determine the sequence of amino acids in protein.


Genetic Counseling

The process of informing a couple about their genetic makeup, which has the potential to affect their offspring.


Genetic Disorder

A disease that has a genetic basis.


Genetic Diversity

The amount of genetic variation within a population or species.


Genetic diversity

The variety of genes within a particular population, species, variety, or breed.


Genetic driftA cumulative process involving the chance loss of some genes and the disproportion ate replication of others over successive generations in a small population, so that the frequencies of genes in the population are altered. The process can lead to a population that differs genetically and in appearance from the original population.

Genetic engineering

The artificial transfer of specific genes from one organism to another.


Genetic resources

Genetic material of actual or potential value.


Gill

In mushrooms, one of the radiating rows on the underside of the cap; in animals, an organ specialized for the exchange of gases with water.


Gizzard

A muscular region of the digestive tract in birds that crushes food.


Gleaning

Collecting of unharvested crops from the fields, or obtaining agricultural products from farmers, processors, or retailers without charge


Gliding Joint

A joint that allows bones to slide over one another, as in foot bones that flex in walking.


Global warming

The term given to the possibility that Earth's atmosphere is gradually warming because of the greenhouse effect of carbon dioxide and other gases. Global warming is thought by many to be the most serious global environmental issue facing our society.


Glomerulus

A cluster of capillaries that receives blood from the renal artery and that is enclosed in Bowman’s capsule.


Glucagon

A hormone that raises the blood glucose level.


Glycolysis

A pathway in which glucose is oxidized to pyruvic acid.


Glycoprotein

A molecule of protein with attached sugar chains.


Grafting

The process of inserting a scion of a specified plant variety into a stem, root, or branch of another plant so that a permanent union is achieved.


Green manure

 A crop planted with the intention of turning it under for use as organic matter


Green manuring crop

Crops grown during rainy season and buried in to the soil by ploughing just at their flowering stage to add organic matter after their decomposition in the soil e.g. Senji, Guara, Dhaincha, Sanhemp are good manuring crops


Green Revolution

The development and introduction of new varieties of wheat and rice (mainly) that increased yields per acre dramatically in some countries.


Greenhouse effect

A natural effect that traps heat in the atmosphere (troposphere) near the earth's surface. Some of the heat flowing back toward space from the earth's surface is absorbed by water vapor, carbon dioxide, ozone, and several other gases in the lower atmosphere (troposphere) and then radiated back toward the earth's surface. If the atmospheric concentrations of these greenhouse gases rise and are not removed by other natural processes, the average temperature of the lower atmosphere will gradually increase.


Greenhouse gasesGases in the earth's lower atmosphere (troposphere) that cause the greenhouse effect. Examples are carbon dioxide, chlorofluorocarbons, ozone, methane, water vapor, and nitrous oxide.

Gross Farm Income

Income which farm operators realize from farming. It includes cash receipts from the sale of farm products, government payments, value of food and fuels produced and consumed on farms, and the rental value of farm dwellings.


Gross primary productivity

The rate at which an ecosystem's producers capture and store a given amount of chemical energy as biomass in a given length of time.


Ground Water

Water beneath the earth's surface between saturated soil and rock, which supplies wells and springs