Environmental Science In Agricultural MCQ Question and Answer | Agriculture MCQ Question

The capacity of the organic and biological matter in a sample of natural water to consume oxygen and the process catalyzed by bacteria is Biological Oxygen Demand (BOD).
Biochemical oxygen demand is an analytical parameter representing the amount of dissolved oxygen (DO) consumed by aerobic bacteria growing on the organic material present in a water sample at a specific temperature over a specific period.
The BOD value is most commonly expressed in milligrams of oxygen consumed per liter of sample during 5 days of incubation at 20°C and is often used as a surrogate of the degree of organic water pollution.

Out of the total water evaporated from the oceans, 10% of water is available to terrestrial ecosystems.
The ocean plays a key role in this vital cycle of water. The ocean holds 97% of the total water on the planet; 78% of global precipitation occurs over the ocean, and it is the source of 86% of global evaporation.
Water controls the dynamics of terrestrial ecosystems directly, as a resource for the biota, and indirectly, as a driver for abiotic processes on the Earth's surface, in the atmosphere, and belowground.

Good soil has 50% organic and inorganic salts and other 50% of pores, air and water.
Soil consists of these major components of inorganic mineral matter, about 40 to 45 percent of the soil volume. organic matter, about 5 percent of the soil volume, water and air, about 50 percent of the soil volume.
A typical soil is about 50% solids (45% mineral and 5% organic matter), and 50% voids (or pores) of which half is occupied by water and half by gas.

Sickel cell anaemia is a molecular disease.
Any disease caused by an abnormality in a single protein, usually an enzyme is known as molecular disease.
Sickle cell anaemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to a rigid, sickle-like shape under certain circumstances.
Sickle cell disease occurs when a person inherits two abnormal copies of the β-globin gene that makes haemoglobin, one from each parent. This gene occurs in chromosome 11. Several subtypes exist, depending on the exact mutation in each haemoglobin gene.

Ultra-violet light causes the destruction of hydrogen bonds between complementary DNA stands.
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun.
Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. The most deadly form of skin cancer, malignant melanoma, is mostly caused by UV radiation.

The term which shows the relationship existing between parts of measures is Correlation.
Correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data.
Correlations are useful because they can indicate a predictive relationship that can be exploited in practice. For example, an electrical utility may produce less power on a mild day based on the correlation between electricity demand and weather.

Halocarbons or halons are constituents of Fire extinguishers.
Halocarbons are carbon compounds that contain fluorine, chlorine, bromine, and iodine. Halocarbons that contain chlorine (CFCs and HCFCs) and bromine (halons) cause ozone depletion.
Clean agents extinguish the fire by displacing oxygen (CO₂ or inert gases), removing heat from the combustion zone or inhibiting the chemical chain reaction. Halon 1301 and 1211 are being replaced with new halocarbon agents which have no ozone depletion properties and low atmospheric lifetimes but are less effective.

Functions performed by a forest help most in controlling drought Forests bring rainfall.
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function.
It helps mitigate natural hazards such as floods. Serving as a genetic reserve. Serving as a source of lumber and as recreational areas. Serving as a source of woodlands and trees millions of people depend almost entirely on forests for subsistence for their essential fuelwood, food and fodder needs.

Most primary productivity in the surface water of lakes and oceans is due to Phytoplankton.
Phytoplanktons are the autotrophic components of the plankton community and a key part of ocean and freshwater ecosystems.
Phytoplankton is photosynthesizing microscopic protists and bacteria that inhabit the upper sunlit layer of marine and freshwater bodies of water on Earth. Paralleling plants on land, phytoplankton undertakes primary production in water, creating organic compounds from carbon dioxide dissolved in the water.

The tropical cyclone is known as Typhoon.
A tropical cyclone is a generic term used by meteorologists to describe a rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has closed low-level circulation. Hurricanes and typhoons are the same weather phenomenon known as tropical cyclones.
A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, accounting for almost one-third of the world's annual tropical cyclones. It is referred to as a mature tropical cyclone in the northeast Pacific and northern Atlantic.