Important terms and brief description

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Important terms and brief description:
Hydroponic culture:
It is the technique in which the plants are grown in aerated water to which nutrients and mineral salts have been added. The purpose of this technique is to test whether a certain nutrient is essential for a plant or not because it is not possible to conduct such experiments on nutrient requirements of plants grown in soil because soil is a complex medium. However, hydroponic farming is not feasible and may only be used for growing vegetables.
Amphipathic molecules:
When the molecules like lipids have both polar and non-polar characteristics, such molecules are called as amphipathic. For example, lipid molecules constituting the plasma membrane have the polar heads facing outwards and non-polar fatty acid chains towards the interior of the membrane.
Transpiration:
It is a specific terminology for water loss in plants. The loss of water from the Arial parts of the plants i.e. leaves and other aerial parts is called transpiration.such loss of water occurs through the stomata.
Evaporation:
The loss of water or the escape of water molecules from the surface of water without the process of boiling is called evaporation.the ultimate cooling behind is the consequence of evaporation because molecules with higher kinetic energy leaves the surface.
Sublimation:
The process that involves direct conversion of the solid into gas without transforming into a liquid is called sublimation.
Condensation:
The conversion of vapours or the gas into liquid form under pressurized condition is called as condensation.
Refrigerators use the technique of condensation to keep the things cold.
Transgenic organisms:
Organisms in which the piece of DNA has been inserted from the external source are called as transgenic organisms and such DNA is called as the recombinant DNA. The selected genes are inserted into the original DNA through cutting pasting to produce better varieties of organisms for various purposes including plants animals and bacteria.
Surface tension:
Liquid molecules have the property of cohesion. it the tendency of liquid to cling together .the molecules at the surface of water are attracted by many molecules below it so the molecules at the surface needs a net inward attraction. This attraction creates surface tension. The water surface acts as a continuous sheet or stretched piece of rubber.
In water the surface tension is credited to hydrogen bonding which build up cohesion forces.
Binomial nomenclature:
Carolus Linneaus first of all proposed the concept of binomial nomenclature in 1735.according to this, every living organism should be named on the basis of scientific standards containing two words, the genus name starting with capital letter followed by the species name starting with small letter. Both should be underlined separately or written in italics. the main purpose of this naming is, so that people belonging to different areas and speaking different languages may not be confused and can collectively discuss the organisms scientifically.
Human beings Homo sapiens
Frog Rana tigrina
Corn Zea mays

Symbiosis:
It is the intimate association in which both partners get benifit.it is also called as mutualism.one partner is called symbiont that forms association with the other called the Host.
For example.Trichonympha a protozoan is a symbiont that lives inside the gut of the termite obtain foods and lodging and in turn helps in the digestion of wood eaten by the termite.

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Saprophytes:
These are the organisms that feed on the dead and decaying material of plants and animals. Fungi are the best example of saprophyte. These are decomposers that decompose the dead organisms and derive nutrients from them.
Velocity:
The velocity of the body at any instant is defined as the change in displacement per second at that instant. It is a vector quantity and is measured as m/sec.
Acceleration:
The change of velocity per unit time is called acceleration. It is defined as the rate of change of velocity. It is measured as m/sec2.
Radiotherapy:
This is the technique that is administered to control cancer. In radiotherapy, the cancerous part is exposed to short wave radiation from the radioactive material repeatedly at regular intervals. In Pakistan there are many centers that are using the technique of radiotherapy to control cancer.
Chemotherapy:
This is also a cancer control therapy. Chemotherapy, as the name indicates involves the use of anticancer chemicals at regular intervals.however, these chemicals may destroy and kill the normal cells along with the cancer cells. Such therapies have a wide range of negative side effects including hair loss.
Clone:
A clone is defined as the cell and all its asexually produced offsprings.the characteristic of clone is that this group of cells is produced asexually and all the cells are genetically identical to each other. And the process by which the animals are produced in clones is called as cloning. In normal conditions, the animals are not produced by cloning, however, still there are certain animals that undergo reproduction by the process of cloning on regular basis like unicellular animals that undergo asexual reproduction.
Eukaryotes:
The word eukaryotic is derived from Greek word, where “eu” means true and “karyon” means nucleus. It is the type of cellular organization in which the cell consists of a distinct membrane bound nucleus containing the hereditary material together with other distinct membrane bound cytoplasmic organelles. Such cells have well defined nucleus, mitochondria, endoplasmic reticulum etc. kingdom animalia, plantae, fungi and protoctista are eukaryotic in organization.
Prokaryotes:
This word is derived from the Greek language where “Pro” means before and “karyon” means nucleus. these are called as the primitive types of cells and considered to be the origin of the eukaryotic cells. These cells don’t have the distinct membrane bound nucleus, and the area in the cytoplasmic matrix that consists of the hereditary material is called Nucleoid.the cytoplasmic matrix do not contain the proper membrane bound organelles and cytoskeleton.the constitution of plasma membrane and cell wall of prokaryotes largely differs from that of the eukaryotic cells.
It forms the kingdom monera consisting of all the archoebacteria, eubacteria and cynobacteria (blue green algae).
Herbivores:
As the name indicates, these are the group of animals that depend solely on the herbs and plant material for their food. Herbivores are also called as the primary consumers they form the second trophic level in the food chain, plants being the first as producers, that are consuming the producers. So these animals get energy directly from producers.Such animals have more developed incisors for gnawing and molars for grinding the food. Example includes all the cattle, birds feeding on seeds and grains, rabbit, squirrel, caterpillar etc
Carnivores:
The group of animals that depends on flesh of other animals for their food is called carnivores. The carnivores are usually categorized as secondary consumers and tertiary consumers in the food chain and food web. The secondary consumers feed on herbivores while tertiary consumers or larger carnivores feed on secondary consumers in other words,these animals get energy indirectly from the producers. They have more developed canines for tearing the flesh. Cats, dogs, shark, snakes, lion, falcon, crocodile, tiger all hunting for their prey are carnivores.
Omnivores:
The animals that depend on both plant and animal material for their food are called omnivores.
Examples includes crow, monkey and man.
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[Wounded Healer]

Antibody
A protein found principally in blood serum and characterized by a specific reactivity with the corresponding antigen. Antibodies are important in resistance against disease, in allergy, and in blood transfusions, and can be utilized in laboratory tests for the detection of antigens or the estimation of immune status.


Biopsy

A biopsy is the removal of a small portion of tissue from the body for microscopic examination.


Hydrodynamics
The study of fluids in motion. The study is based upon the physical conservation laws of mass, momentum, and energy. The mathematical statements of these laws may be written in either integral or differential form. The integral form is useful for large-scale analyses and provides answers that are sometimes very good and sometimes not, but that are always useful, particularly for engineering applications.


Hydrostatics
The study of liquids at rest. In the absence of motion, there are no shear stresses; the internal state of stress at any point is determined by pressure alone. Hence, the pressure at a point is the same in all directions. Pressure acts normally to all boundary surfaces. For equilibrium under gravity, regardless of the shape of the containing vessel, the pressure is uniform over any horizontal cross section. Pressure varies with height or depth.


Osmosis

The term osmosis describes the movement of a solvent through a semipermeable membrane from a less concentrated solution to a more concentrated one. Water is sometimes called "the perfect solvent," and living tissue (for example, a human being's cell walls) is the best example of a semipermeable membrane. Osmosis has a number of life-preserving functions: it assists plants in receiving water, it helps in the preservation of fruit and meat, and is even used in kidney dialysis. In addition, osmosis can be reversed to remove salt and other impurities from water.


Photoperiodism
The growth, development, or other responses of organisms to the length of night or day or both. Photoperiodism has been observed in plants and animals, but not in bacteria (prokaryotic organisms), other single-celled organisms, or fungi.


Transistor
A solid-state device involved in amplifying small electrical signals and in processing of digital information. Transistors act as the key element in amplification, detection, and switching of electrical voltages and currents. They are the active electronic component in all electronic systems which convert battery power to signal power. Almost every type of transistor is produced in some form of semiconductor, often single-crystal materials, with silicon being the most prevalent. There are several different types of transistors, classified by how the internal mobile charges (electrons and holes) function. The main categories are bipolar junction transistors (BJTs) and field-effect transistors (FETs).

Autopsy

An autopsy is a postmortem assessment or examination of a body to determine the cause of death. An autopsy is performed by a physician trained in pathology.
Most autopsies advance medical knowledge and provide evidence for legal action. Medically, autopsies determine the exact cause and circumstances of death, discover the pathway of a disease, and provide valuable information to be used in the care of the living.


Biodegradability

Capacity of a material to decompose by biological action. The term usually refers to the environmental breakdown of waste by microorganisms. Generally, plant and animal products are biodegradable, whereas mineral substances (e.g., metals, glass, plastics) are not. Local conditions, especially the presence or absence of oxygen, affect biodegradability. Disposal of non-biodegradable waste is a primary source of pollution. Surgical materials made to be absorbed by the body are also called biodegradable.



Fluorescence

Fluorescence is generally defined as a luminescence emission that is caused by the flow of some form of energy into the emitting body, this emission ceasing abruptly when the exciting energy is shut off. In attempts to make this definition more meaningful it is often stated, somewhat arbitrarily, that the decay time, or afterglow, of the emission must be of the order of the natural lifetime for allowed radiative transitions in an atom or a molecule, which is about 10?8 s for transitions involving visible light.



Nitrogen cycle

The collective term given to the natural biological and chemical processes through which inorganic and organic nitrogen are interconverted. It includes the process of ammonification, ammonia assimilation, nitrification, nitrate assimilation, nitrogen fixation, and denitrification.


Pasteurization

The treatment of foods or beverages with mild heat, irradiation, or chemical agents to improve keeping quality or to inactivate disease-causing microorganisms. Originally, Louis Pasteur observed that spoilage of wine and beer could be prevented by heating them a few minutes at 122–140°F (50–60°C)


Short circuit

A short circuit (sometimes abbreviated to short or s/c) is an accidental low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages. This results in an excessive electric current limited only by the Thevenin equivalent resistance of the rest of the network and potentially causes circuit damage, overheating, fire or explosion.

Aqua regia

Aqua regia (Latin for "royal water") is a highly corrosive, fuming yellow or red solution. The mixture is formed by freshly mixing concentrated nitric acid and concentrated hydrochloric acid, usually in a volumetric ratio of one to three. It is one of the few reagents that dissolves gold and platinum. It was so named because it can dissolve the so-called royal, or noble metals, although tantalum, iridium, and a few other metals are able to withstand it.



Dialysis
In medicine, dialysis is a type of renal replacement therapy which is used to provide an artificial replacement for lost kidney function due to renal failure. It is a life support treatment and does not treat any kidney diseases. Dialysis may be used for very sick patients who have suddenly lost their kidney function (acute renal failure) or for quite stable patients who have permanently lost their kidney function (end stage renal failure).



Allele
In genetics, an allele (pronounced al-eel or al-e-ul) is any one of a number of viable DNA codings occupying a given locus (position) on a chromosome. Usually alleles are DNA (deoxyribonucleic acid) sequences that code for a gene, but sometimes the term is used to refer to a non-gene sequence. An individual's genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype. The word came from Greek αλληλος = "each other".

Iodised salt

Iodised salt (AmE: iodized salt) is table salt mixed with a minute amount of iodide salts to help reduce the chance of iodine deficiency, which can lead to thyroid gland problems, the most common being goiter. Only tiny quantities of iodine are required in a diet to prevent this disease, but there are many places around the world where natural levels of iodine in the soil are low and the iodine is not taken up by vegetables.



Optical Fiber

An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by total internal reflection. Fiber optics is the branch of applied science and engineering concerned with such optical fibers. Optical fibers are widely used in fiber-optic communication, which permits digital data transmission over longer distances and at higher data rates than other forms of wired and wireless communications. They are also used to form sensors, and in a variety of other applications.



Radioactive Decay

Radioactive decay is the set of various processes by which unstable atomic nuclei emit subatomic particles (radiation). Decay is said to occur in the parent nucleus and produces a daughter nucleus. This is a random process, i.e. it is impossible to predict when an atomic nucleus will decay or which nuclei in a sample will.


Pesticide

A pesticide may be a chemical substance or biological agent (such as a virus or bacteria) used against pests including insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms) and microbes that compete with humans for food, destroy property, spread disease or are a nuisance. Many pesticides are poisonous to humans.



Pollination

Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). The receptive part of the carpel is called a stigma in the flowers of angiosperms and a micropyle in gymnosperms. The study of pollination brings together many disciplines, such as botany, horticulture, entomology, and ecology. Pollination is important in horticulture because most plant fruits will not develop if the ovules are not fertilized. The pollination process as interaction between flower and vector was first addressed in the 18th century by Christan Konrad Sprengel.