Refraction is the change in direction of a wave passing from one medium to another caused by its change in speed. For example waves in deep water travel faster than in shallow.

Refraction is described by Snell's law, which states that, for a given pair of media and a wave with a single frequency, the ratio of the sines of the angle of incidence θ1 and angle of refraction θ2 is equivalent to the ratio of phase velocities (v1 / v2) in the two media, or equivalently, to the opposite ratio of the indices of refraction (n2 / n1).

Photosynthesis is the process by which plants turn light energy into chemical energy. Plants also need carbon dioxide and water along with the light to complete the process. The byproducts of photosynthesis is oxygen . The sugars that the plant creates gives it energy and helps create carbohydrates in food producing plants. Carbohydrates are essential to those organisms that feed on these plants to fuel processes in their own bodies.Chlorophyll, which is a green pigment, is the main molecule that traps energy in plants. Chlorophyll is found in the chloroplasts of plant cells.

Salivary Amylase  is the name of enzyme.

The process of digestion starts the moment food enters your mouth. The mouth and esophagus themselves don’t make any enzymes, but saliva, produced in the salivary glands and excreted into the mouth, and down into the esophagus, contains several important enzymes such as amylase, lysozyme and lingual lipase. Saliva is mixed with food as you chew, and acts as a lubricant to start the digestion process. The enzymes in saliva start to break down nutrients, while some also help protect you from bacteria and support the body's immune system.

There are five key processes by which soil is formed, they are:

Leaching - leaching is the removal of soluable components of the soil column.

Eluviation - here soil particles held in suspension, such as clay, are removed (eg. washed away).

Illuviation - here soil particles held in suspension, such as clay, are accumulated (eg. deposited).

Podsolisation - podsolisation occurs when strongly acid soil solutions cause the breakdown of clay minerals. As a result silica, aluminium and iron form complexes with organic substances in the soil. 

Gleying - gleying occurs in waterlogged, anaerobic conditions when iron compounds are reduced and either removed from the soil, or segregated out as mottles or concretions in the soil. Marshy wetlands often contain gleyed soils.

the process of providing or obtaining the food necessary for health and growth.

Conductors are materials that allow free flow of electrons from one particle to another. These are elements which have electric charges in the form of electrons that are comparatively free to move inside the material.

Some of the common example of conductors includes metals such as copper, gold, iron, etc. Graphite, human body and the earth are also good conductors of electricity.

The best soil to growth cotton is Black soil.

While both tropical cyclones and tornadoes are atmospheric vortices, they have little in common.

Tornadoes have diameters on the scale of 100s of meters and are produced from a single convective storm (i.e. a thunderstorm or cumulonimbus).

A tropical cyclone, however, has a diameter on the scale of 100s of *kilometers* and is comprised of several to dozens of convective storms.

Additionally, while tornadoes require substantial vertical shear of the horizontal winds (i.e. change of wind speed and/or direction with height) to provide ideal conditions for tornado genesis.

Tropical cyclones require very low values of tropospheric vertical shear in order to form and grow. These vertical shear values are indicative of the horizontal temperature fields for each phenomenon.

Tornadoes are produced in regions of large temperature gradient, while tropical cyclones are generated in regions of near zero horizontal temperature gradient.

Tornadoes are primarily an over-land phenomena as solar heating of the land surface usually contributes toward the development of the thunderstorm that spawns the vortex (though over-water tornadoes have occurred).

In contrast, tropical cyclones are purely an oceanic phenomena - they die out over-land due to a loss of a moisture source.

Lastly, tropical cyclones have a lifetime that is measured in days, while tornadoes typically last on the scale of minutes.

The lungs are a primary source of our energy level. They extract oxygen from the air we breathe primarily on the exhale. Because the nostrils are smaller then the mouth, air exhaled through the nose creates back pressure when one exhales. It slows the air escape so the lungs have more time to extract oxygen from them.