Answer the question on basis of passage given below :
In zwitter ionic form, amino acids show amphoteric behaviour as they react both with acids and bases.
Except glycine, all other naturally occurring \(\alpha\) - amino acids are optically active, since the \(\alpha\) -carbon atom is asymmetric. These exist both in 'D' and 'L' forms. Most naturally occurring amino acids have L-configuration. L-Aminoacids are represented by writing the \(-NH_2\) group on left hand side.
Optically inactive amino acid from the following is :

Salicylaldehyde is formed as a main product from phenol by :

Which of the following process does not occur at the interface of phases?

1.00 g of a non-electrolyte solute when dissolved in 50 g of organic solvent,
lowered the freezing point of the organic solvent by 0.50 K. If the freezing point depression constant of the organic solvent is \(5 K kg mol ^{-1}\), the molar mass of the solute will be

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Biomolecules are the organic compounds present as an essential constituents of living organisms in different cells. molecules are generally termed as macromolecules, which are carbohydrates, enzymes, nucleic acids, amino acids and proteins The etc. Carbohydrates are classified as sugars and non-sugars include sucrose, glucose, fructose, starch and cellulose. Enzymes are coordinated with various chemical reactions in nucleic acid. Nucleic acids are found in living organisms made up of proteins and atural polymers. Two types that are generally found in biological systems are DNA and RNA nucleic acid. Amino acids bifunctional groups of carboxyl and amino groups. Proteins are a class of biologically important compounds. They are crucial are to virtually all processes in living systems. Some of them are hormones, which serve as chemical messengers that coordinate certain biochemical activities.
Starch is a polymer of saccharides known as

A molecule X associates in a given solvent as per the following equation: \(X \rightleftharpoons(X) n\). For a given concentration of \(X\), the van't Hoff factor was found to be \(0 . 8 0\), and the fraction of associated molecules was \(0 . 3\). The correct value of ' \(n\) ' is:

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Amines are considered as derivatives of ammonia obtained by replacement of hydrogen atoms with alkyl or aryl groups. In nature they occur among proteins, vitamins, alkaloids and hormones. These can be primary, secondary or tertiary depending on the number of hydrogen groups replaced. They can be prepared from nitro compounds, alkyl halides, nitriles, amides etc. Due to unshared pair of electrons they behave as Lewis bases. Influence of the number of hydrogen atoms at nitrogen atom is displayed in physical properties such as solubility, boiling point and chemical reactions including basicity. Basic character of amines is expressed in terms of their \(K_b\) and \(p K_b\) values. Three classes of amines can be distinguished with p-toluene sulphonyl chloride which reacts with primary and secondary ddu amines. Amino group when attached to benzene ring behaves as an activating and ortho para directing group.
Which of the following is a tertiary amine?

Among the following, which is a non-essential amino acid?

A charge of \( 5 \mu C \) moves with a speed of \( 2 \times 10^6 \text{ m/s} \) along the positive \( y \)-axis. A magnetic field \( \vec{B} \) of strength \( (2\hat{i} + \hat{k})\text{T} \) exists in space. The magnetic force acting on the charge is :

Read the passage and answer the question given below. When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation or infectious organisms gaining access into body during natural infection induce active immunity. When antibodies are directly given to protect the body against foreign agents, it is called passive immunity.
which is passive immunisation?

Answer the question on the basis of passage given below :
Adsorption is a surface phenomenon and it differs from absorption which occurs throughout the body of the substance that absorbs. In physiosorption the attractive forces are mainly van der Waal's forces while in chemisorption ionic/covalent bonds are formed between particles of adsorbent and adsorbate. The catalytic activity of finely divided iron in Haber's process of ammonia manufacture can be explained by adsorption theory. Adsorption being an exothermic process, the heat of adsorption is utilised in enhancing the rate of the reaction. Adsorption has many applications being used in gas masks, control of humidity, chromatograph separation, curing diseases etc.
Which of the following is not a surface phenomenon?

Let * be a binary operation defined on \(Q ^{+}\)(the set of positive rational numbers) by the rule \(a * b=\frac{a b}{7}\) for all \(a, b \in Q ^{+}\). Then inverse of \(2 * 7\) is:

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Biofertilisers
Biofertilisers are organisms that enrich the nutrient quality of the soil and their main sources are bacteria, fungi and cyanobacteria. You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria can fix atmospheric nitrogen into organic forms. Other bacteria can also fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter). Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development. Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter in to the soil and increase its fertility. Currently, in our country, a number of biofertilisers are available commercially in the market and farmers use these regularly in their fields to replenish soil nutrients and to reduce dependence on chemical fertilisers.
Nostoc is an example of :