Which of the following is not a nitrogen fixing micro organism?

Arrange the following geological periods in their occurrence from latest to oldest order.
(A) Triassic
(B) Carboniferous
(C) Tertiary
(D) Jurassic
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A nucleoside comprises:

Among vertebrates, the maximum number of species belong to

Read the following passage carefully and answer the given questions.
Plasmodium, a tiny protozoan is responsible for the disease malaria. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal. Innate immunity consist of four types of barriers. These are – (i) Physical barriers- skin on our body is the main barrier which prevents entry of the micro-organisms. (ii) Physiological barriers- Acid in the stomach, saliva in the mouth, tears from eyes-all prevent microbial growth. (iii) Cellular barriers- Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. (iv) Cytokine barriers- virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection. Allergy is due to the release of chemicals like histamine and serotonin from the mast cells. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused.
Malignant malaria is caused by _____ is the most serious one and can even be fatal.

Which one of the given groups of structures are haploid?

In eukaryotes, RNA polymerase III transcribes:
(A) tRNA
(B) 5.8S rRNA
(C) 5srRNA
(D) snRNA
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Answer the question on the basis of passage given below :
Formaldehyde is the first member of the aldehydic series. It is present in green leaves of plants where its presence is supposed to be due to the reaction of \(CO_2\) with water in the presence of sunlight and chlorophyll. Commercially, formaldehyde is obtained by the controlled oxidation of methane in the presence of molybdenum oxide (\(MoO\)) acting as a catalyst. Formaldehyde is a constituent of a number of polymers also called resins. These are non volatile solids or semi solids which are obtained directly from certain plants and can be synthesized in the laboratory.
Match List I with List II

LIST I	LIST II
A. Bakelite formaldehyde resin	I. Condensation polymers
B. Melamine formaldehyde resin	II. Phenol and formaldehyde
C. Urea formaldehyde resin	III. Melamine and formaldehyde
D. Bakelite \(\&\) Melamine formaldehyde resin	IV. Unbreakable cups and laminated sheets

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Answer the question on the basis of passage given below :
Formaldehyde is the first member of the aldehydic series. It is present in green leaves of plants where its presence is supposed to be due to the reaction of \(CO_2\) with water in the presence of sunlight and chlorophyll. Commercially, formaldehyde is obtained by the controlled oxidation of methane in the presence of molybdenum oxide (\(MoO\)) acting as a catalyst. Formaldehyde is a constituent of a number of polymers also called resins. These are non volatile solids or semi solids which are obtained directly from certain plants and can be synthesized in the laboratory.
Benzaldehyde is less reactive towards nucleophilic addition reaction than formaldehyde because of:

Which of the following statements are correct?
(A) A lion eating a deer and a sparrow feeding on grains are ecologically similar consumers.
(B) Predator star fish Pisaster helps in maintaining the species diversity of some invertebrates.
(C) Predators ultimately lead to the extinction of prey species.
(D) Production of chemicals such as nicotine and strychnine by the plants are metabolic disorders.
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If \(y=\sin ^{-1}\left(\frac{1-x^2}{1+x^2}\right)\) then \(\frac{d y}{d x}=\)

Fructose is a ketohexose. The keto group is positioned at which carbon:

Out of all isomers of \(\text{C}_4\text{H}_{11}\text{N}\), how many are primary amines?