Observe the table and answer the given question :

How many codons with 'A' at second position code for amino acids ?

Arrange the following steps of Polymerase Chain Reaction in correct sequence.
A. Annealing of Primer
B. Denaturation of dsDNA
C. Extension of Primer
D. Amplification
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Observe the table and answer the given question :

How many amino acids have only two codons coding for them each ?

Read the passage carefully and answer the questions given along
Our immune system plays the major role in preventing diseases when we are exposed to disease-causing agents. Immunity is of two types: (i) Innate immunity and (ii) Acquired immunity. The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. The immune system also plays an important role in allergic reactions, auto-immune diseases and organ transplantation. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs are spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa associated lymphoid tissue (MALT). It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. AIDS has no cure, prevention is the best option. Adolescence is accompanied by several biological and behavioural changes and surveys and statistics show that use of drugs and alcohol has been on the rise especially among the youth. Factors associated with drug and alcohol abuse among adolescents are a child's natural curiosity, stress, the perception among youth that it is 'cool' or progressive to smoke, media exposure and an unstable or unsupportive family structures and peer pressure. It is best to identify the situations that may push an adolescent towards use of drugs or alcohol, and to take remedial measures well in time.
Which one of the following structures is not an example of a cellular barrier in innate immunity?

What kind of IUD is Lippes loop?
A. Non-medicated
B. Copper releasing
C. Zinc releasing
D. Hormone releasing E. Medicated IUDs
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The animal used to test the safety of polio vaccine is.

Arrange the following in order of their appearance, if a sperm starts travelling from testicular lobules?
(A) Urethra
(B) Vas deferens
(C) Urethral meatus
(D) Vasa efferentia
Choose the correct answer from the options given below:

Diodes are most commonly used for rectification of alternating voltages. This is because, in diode
(A) current flows in one direction only
(B) forward bias resistance is low as compared to reverse bias resistance
(C) reverse current is independent of the voltage applied
(D) reverse current is linearly dependent on the voltage applied
Choose the correct answer from the options given below:

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Carboxylic acids are the organic compounds which comprise of carboxyl functional group, -COOH. These are generally found in nature, some higher members are known as fatty acids as they occur in natural fats as esters of glycerol. They can be prepared from oxidation of alcohols and aldehydes, hydrolysis of nitriles and amides and Grignard reagents. They are stronger acids than simple phenols and alcohols. but weaker than mineral acids. Substituents affect the acidity of aliphatic and aromatic carboxylic acids. They undergo reactions involving cleavage of -OH and C-OH bond. Carboxylic acids having an alpha hydrogen get halogenated in the presence of red phosphorus to form alpha halo carboxylic acids. The reaction is known as Hell Volhard Zelinsky reaction. Besides these aromatic carboxylic acids undergo electrophilic substitution reactions. They are versatile and are employed in the manufacture of various useful compounds. For example, methanoic acid is used in rubber, textile, dyeing, leather and electroplating industries. Higher fatty acids are used in the manufacture of soaps and detergents. Esters of Benzoic acid are used in perfumery.
Benzoic acid in the presence of conc. \(HNO _3\) and conc. \(H _2 SO _4\) gives major product as:

Which of the following statements is NOT correct regarding the catalytic ability of transition metals?

Diameter of the objective lens of a telescope is 250 cm. For light of wavelength 600 nm, coming from a distant object, the limit of resolution of the telescope is close to :

What is the oxidation number of the metal of \([Co(H_2O)(CN)(ox)_2]^{2-}\) coordination entity?

Glycosidic linkage is formed by :