BHU Agriculture Entrance Practice Set 1

Explanation: Dr. M.S. Swaminathan is known as the 'Father of the Green Revolution in India'. He introduced high-yielding varieties of wheat (developed by Norman Borlaug) and rice to Indian agriculture in the 1960s, transforming India from a food-deficit to a food-surplus nation.

Explanation: Intercropping is the practice of growing two or more crops simultaneously in the same field in a definite row arrangement. It differs from mixed cropping (no row pattern), relay cropping (sequential planting before previous crop harvest), and crop rotation (sequential in different seasons).

Explanation: Most agricultural crops grow best in a soil pH range of 6.0-7.5 (slightly acidic to neutral). At this pH, most essential nutrients are available in adequate quantities and soil microbial activity is optimal.

Explanation: Disguised unemployment means that more workers are employed on a farm than are actually needed. Removing some workers would not reduce total output. It is a major problem in Indian agriculture due to small landholdings and seasonal nature of farming.

Explanation: Potato tubers (seed potatoes) are planted at a depth of 5-7 cm in loose, well-drained soil. Shallow planting exposes tubers to sunlight (causing greening and solanine production), while deeper planting delays emergence.

Explanation: Olericulture is the branch of horticulture dealing with the study and cultivation of vegetables. Kitchen gardening (growing vegetables for home consumption) is a practical application of olericulture.

Explanation: Vermicompost is a nutrient-rich organic fertiliser prepared using earthworms (vermis = worm). Species like Eisenia foetida (red wiggler) and Eudrilus eugeniae (African nightcrawler) decompose organic waste into humus-rich compost.

Explanation: Ribosomes are the cellular organelles responsible for protein synthesis (translation). They read the mRNA sequence and assemble amino acids into polypeptide chains. They are found free in the cytoplasm or attached to the rough endoplasmic reticulum.

Explanation: Osmosis is the movement of water molecules from a region of higher water potential (dilute solution in the soil) to a region of lower water potential (concentrated cell sap in root hair cells) through a selectively permeable membrane.

Explanation: Mendel's law of segregation (first law) states that each organism carries two alleles for each trait and these alleles separate (segregate) during gamete formation, so each gamete receives only one allele. This was confirmed by the 3:1 ratio in F2.

Explanation: Tropical rainforests have the highest biodiversity of any terrestrial biome, containing over 50% of the world's plant and animal species despite covering only about 6-7% of Earth's land surface. This is due to high temperature, rainfall, and solar energy year-round.

Explanation: R.H. Whittaker proposed the five-kingdom classification in 1969, dividing all living organisms into Monera, Protista, Fungi, Plantae, and Animalia based on cell structure, body organisation, mode of nutrition, reproduction, and phylogenetic relationships.

Explanation: The liver is the largest gland in the human body, weighing about 1.5 kg in adults. It performs over 500 functions including bile secretion, detoxification, protein synthesis, glycogen storage, and metabolism of fats, proteins, and carbohydrates.

Explanation: Pollination is the transfer of pollen grains from the anther (male part) to the stigma (female part) of a flower. It can be self-pollination (same flower) or cross-pollination (different flower), mediated by wind, water, insects, or other agents.

Explanation: Restriction endonucleases are molecular scissors that cut DNA at specific recognition sequences (usually palindromic, 4-8 bp long). They are essential tools in recombinant DNA technology for cutting DNA from different sources to create recombinant molecules.

Explanation: Force is measured in newton (N); joule is energy, watt is power, pascal is pressure.

Explanation: The specific heat capacity of water is approximately 4.18 J/(g·°C) or 4186 J/(kg·K). Water has one of the highest specific heat capacities of any common substance, which is why it is an excellent coolant and temperature moderator in agricultural and biological systems.

Explanation: Total internal reflection occurs when light travels from a denser medium to a rarer medium (e.g., glass to air) and the angle of incidence exceeds the critical angle. All light is reflected back into the denser medium with no refraction.

Explanation: The SI unit of electrical resistance is the Ohm (Ω), named after Georg Simon Ohm. One Ohm is the resistance between two points of a conductor when a constant potential difference of 1 Volt produces a current of 1 Ampere.

Explanation: The photoelectric effect, explained by Einstein in 1905, demonstrates the particle nature of light. Electrons are emitted from a metal surface when light of sufficient frequency (not just intensity) strikes it, proving that light carries energy in discrete packets (photons).

Explanation: The atomic number (Z) of an element equals the number of protons in the nucleus of its atom. In a neutral atom, this also equals the number of electrons. It uniquely identifies each element in the periodic table.

Explanation: Le Chatelier's principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system shifts in the direction that tends to counteract the change and re-establish equilibrium.

Explanation: In an electrochemical cell, oxidation (loss of electrons) occurs at the anode. The mnemonic 'An Ox' (Anode = Oxidation) helps remember this. Electrons flow from the anode through the external circuit to the cathode where reduction occurs.

Explanation: CH₃COCH₃ is acetone, whose IUPAC name is propan-2-one. It is the simplest ketone with three carbon atoms, and the carbonyl group is on the second carbon. The suffix '-one' indicates a ketone functional group.

Explanation: Starch is a polysaccharide made up of glucose monomers linked by alpha-glycosidic bonds. It consists of two components: amylose (linear, alpha-1,4 linkages) and amylopectin (branched, alpha-1,4 and alpha-1,6 linkages). It is the main storage carbohydrate in plants.

Explanation: Rice is India's largest food crop by production, with India being the second-largest rice producer in the world (after China). India produces over 130 million tonnes of rice annually, and it is the staple food for over 65% of the population.

Explanation: PMFBY (launched in 2016) is a crop insurance scheme that provides financial support to farmers in the event of crop failure due to natural calamities, pests, or diseases. Premium rates are 2% for Kharif, 1.5% for Rabi, and 5% for commercial/horticultural crops.

Explanation: Ozone (O₃) is a triatomic allotrope of oxygen. The ozone layer in the stratosphere (15-35 km altitude) absorbs 97-99% of the Sun's harmful ultraviolet radiation, protecting life on Earth. Ground-level ozone is a pollutant.

Explanation: India is the world's largest milk producer, contributing about 24% of global milk production with over 230 million tonnes annually. This achievement is largely due to Operation Flood (White Revolution) pioneered by Dr. Verghese Kurien.

Explanation: Eutrophication is the enrichment of water bodies with nutrients, primarily nitrogen and phosphorus (from agricultural runoff, sewage, and fertilisers). This leads to excessive algal growth (algal blooms), oxygen depletion, and death of aquatic organisms.