PERIPHERAL   :   

The external devices like printers, disk drives, display monitors, keyboards, mouse, etc. that are attached to a computer are known as peripherals.

PERMAFROST   :   

Soil that stays in a frozen state for more than two years in a row.

PERTURB   :   

To cause a planet or satellite to deviate from a theoretically regular orbital motion.

PETROLOGY   :   

The branch of science under geology that studies the origin, occurrence, formation, structure and composition of mineral assemblages and classification of rocks is known as petrology.

PHARMACOLOGY   :   

Pharmacology is the study of drugs and their interactions with the human body (or test animal). A branch of medicine.

PHOBIA   :   

The anxiety disorder exhibited by a person that is related to extreme and irrational fear of simple things or social situations is known as phobias.

PHOSPHATASE   :   

The enzyme that hydrolyzes esters of phosphoric acid by removing phosphate group are known as phosphatase.

PHOSPHODIESTER BOND   :   

A phosphate group joined with the adjacent carbons through easter linkages is known as phosphodiester bond.

PHOTOLYSIS   :   

A chemical process by which molecules are broken down into smaller units through the absorption of light.

PHOTOSPHERE   :   

The visible surface of the Sun; the upper surface of a convecting layer of gases in the outer portion of the sun whose temperature causes it to radiate light at visible wavelengths; sunspots and faculae are observed in the photosphere.

PHOTOSYNTHESIS   :   

A process in green plants and some bacteria during which light energy is absorbed by chorophyll-containing molecules and converted to chemical energy (the light reaction). During the process, carbon dioxide is reduced and combined with other chemical elements to provide the organic intermediates that form plant biomass (the dark reaction). Green plants release molecular oxygen (02), which they derive from water during the light reaction.

PHOTOVOLTAIC   :   

Producing an electric current as the result of light striking a metal; the direct conversion of radiant energy into electrical energy.

PHREATIC ERUPTION   :   

A volcanic eruption or explosion of steam, mud or other material that is not incandescent; this form of eruption is caused by the heating and consequent expansion of ground water due to an adjacent igneous heat source.

PHYLUM   :   

The largest generally accepted groupings of animals and other living things with certain evolutionary traits.

PHYSICAL QUANTITY   :   

Physical quantity has a magnitude i.e. number showing the value and a unit that it is measured in.

PHYSICS   :   

The branch of science that studies matter and energy and its motion and interactions and all that is derived from it like force is known as Physics.

PHYTOPLANKTON   :   

Microscopic plants that live in the water column of oceans, seas, and bodies of fresh water and are the foundation of the marine food chain.

PLAGE   :   

Bright regions seen in the solar chromosphere.

PLANAR FEATURES   :   

Microscopic features in grains of quartz or feldspar consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain's crystal structure.

PLANCK'S CONSTANT   :   

It is the constant which decides the size of the photon, which is a quantum of electromagnetic radiation. This constant also decides the limits of accuracy with which any two complementary quantities can be measured. Planck's Constant is equal to 6.62 x 10 -34 Joule seconds.

PLANCK'S LAW   :   

Planck's law exactly describes the the radiation spectrum of an electromagmetic radiation at all wavelengths emitted from ablack body at temperature 'T. E=hf. (where, E= energy of photon, h= Planck's constant and f= frequency of wave.)

PLANET   :   

The large, spherical body made of rocks and ice orbiting the Sun or another star is known as planet.

PLANITIA   :   

Broad plains that occupy lowlands on planetary surfaces.

PLANUM   :   

A plateau or high plain.

PLASMA   :   

A extremely hot low-density matter in which the individual atoms are charged, even though the total number of positive and negative charges is equal, maintaining an overall electrical neutrality.

PLATE TECTONICS   :   

A concept stating that the crust of the Earth is composed of crustal plates moving on the molten material below.

PLUMES   :   

The hot, feather-like rising gas in the atmosphere of a star or planet that is due to convection is known as plumes.

POINT SOURCE   :   

An identifiable and confined discharge point for one or more water pollutants, such as a pipe, channel, vessel, or ditch.

POLARIZATION   :   

A special property of light; light has three properties, brightness, color and polarization.

POLYSACCHARIDE   :   

Sugars or carbohydrates made up of more than one sugar unit (monosaccharide). See 'carbohydrates' for more information.

PON   :   

The structure located on the brain stem, above the medulla, below the mid brain and anterior to the cerebellum in humans and other bipeds, is known as pon.

POPULATION   :   

The totality of a closely related number of individual organisms that belong to the same species and live in the same geographical area and interact with each other through sexual (or asexual for bacteria) reproduction.

POPULATION MOMENTUM   :   

The impetus for continued expansion of the number of people in a country when the age structure is characterized by a large number of children. Even if birth control efforts are effective in the adult community and the number of new births per person decreases, the number of people in the country expands as the large population of children reach reproductive age.

POROSITY   :   

The total volume of soil, rock, or other material that is occupied by pore spaces. A high porosity does not equate to a high permeability because the pore spaces may be poorly interconnected.

POT OF GOLD   :   

A hidden treasure, many of which can be found in Reeko's Mad Scientist Lab.

PREBIOTIC   :   

Prebiotic refers to the state of matter before life existed, but was conducive to the formation of life (the origin of life). The prebiotic 'soup' is the mixture of organic molecules in bodies of water that are thought to have spontaneous, self-assembly property for the first formation of an organic complex with self-replicating qualities.

PRECAMBRIAN   :   

A geological term denoting the time in Earth history prior to 570 million years ago.

PRECAUTIONARY PRINCIPLE   :   

The belief that if a technology, chemical, physical agent, or human activity can be reasonably linked to adverse effects on human health or the environment, then controls should be implemented even if the problem or the cause-effect relationship is not fully understood; to wait for scientific certainty (or near certainty) is to court disaster.

PRESSURE RIDGE   :   

A ridge formed by the uplift of a lava flow crust due to pressure of the flowing lava.

PRIMARY AIR POLLUTANTS   :   

Pollutants that are pumped into our atmosphere and directly pollute the air. Examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal as well as nitrogen oxides, hydrocarbons, and particulate matter (both solid and liquid).

PRIMARY PRODUCERS   :   

Organisms that produce organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis. Primary production is distinguished as either net or gross. All life on earth is directly or indirectly reliant on primary production.

PRIMARY STRUCTURE   :   

The primary structure of a protein is the sequence of its amino acid components.

PROKARYOTES   :   

Organisms without a cell nucleus, or any other membrane-bound organelles. Most are unicellular, but some prokaryotes are multicellular. The prokaryotes are divided into two domains: the bacteria and the archaea.

PROMINENCE   :   

An eruption of hot gases above the photosphere of the Sun. Prominences are most easily visible close to the limb of the Sun, but some are also visible as bright streamers on the photosphere.

PROMONTORIUM   :   

A cape.

PROTEIN   :   

Proteins are macromolecules made from twenty different types of amino acids. Proteins constitute the active component of cells . Proteins function as enzyme in metabolism, transporters and receptors in cell membranes, hormones, antibodies, and help read, translate, and replicate the genetic information.

PROTONS   :   

A positively charged subatomic particle. Protons, along with other subatomic particles called Neutrons, make up the nucleus of a atom. The number of protons in an atom is called the atomic number of the element. Compare to electrons.

PSEUDOCRATER   :   

A generally circular crater produced by a phreatic eruption resulting from emplacement of a lava flow over wet ground.

PSYCHOLOGY   :   

The branch of science that deals with the science and study of mental life. Psycology is the only science without a specific definition.

PULSAR   :   

A rotating star or a pair of stars that emit electromagnetic radiation characterized by rapid frequency and regularity is known as pulsar.

PUMICE   :   

A light vesicular form of volcanic glass with a high silica content; it is usually light in color and will float on water.

PYROCLASTIC   :   

Pertaining to clastic (broken and fragmented) rock material formed by volcanic explosion or aerial expulsion from a volcanic vent.