Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. It increases the hardness of soap
- B. It increases the solubility of soap in water
- C. It decreases the solubility of soap in water
- D. It decreases the surface tension of water
Explanation: The solubility of soap in water depends upon the non-ionic or carbohydrate part of soap, as the sodium chloride is added in the hot…
Correct answer: It decreases the solubility of soap in water- A. Soaps and detergents both are used only in soft water
- B. Soaps and detergents both are used in soft as well as hard water.
- C. Soap is used only in soft water while detergent can be used in soft as well as hard water
- D. Detergent is used only in soft water while soap is used in soft and hard water, both
Explanation: Sodium-potassium ions that are present in the ionic part of soap form scum with calcium and magnesium ions of hard water and get…
Correct answer: Soap is used only in soft water while detergent can be used in soft as well as hard water- A. Gasoline
- B. Potassium palmitate
- C. Soap
- D. Potassium pentanoate
Explanation: Potassium pentanoate does not have cleaning property because it has less than 8 carbon atoms.
Correct answer: Potassium pentanoate- A. Caustic potash
- B. Glycerine
- C. Potassium glycolate
- D. Potassium stearate
Explanation: Bathing soap are Na+ or K+ salts of carboxylic acid. Potassium stearate is K+ salt of carboxylic acid (C17H35CO2K).
Correct answer: Potassium stearate- A. Sodium propionate + Gum + Glycemle
- B. Sodium palmitate + Glycerine
- C. Sodium potassium stearate + Gum + Glycerine
- D. Sodium stearate + Wax + Glycerine
Explanation: To produce stable, slick and soft lather some other ingredients like Gum and Glycerine is added with regular soap like Sodium potassium…
Correct answer: Sodium potassium stearate + Gum + Glycerine- A. SO2Cl
- B. CaCl2
- C. ZnO
- D. Conc. H2SO4
Explanation: In the preparation of soap by hydrolysis of fat using steam in presence of catalyst ZnO, the ester linkage bond breaks into glycerol and…
Correct answer: ZnO- A. Triglyceride
- B. Oil and fat
- C. Soap
- D. Ester
Explanation: Soaps are Sodium Potassium salts of Carboxylic acids not Triacylglycerol.
Correct answer: Soap- A. Calcium salt of stearic acid
- B. Calcium salt of heptadecanesulphonic acid
- C. Magnesium salt of laurylsulphonic acid
- D. Potassium salt of palmitic acid
Explanation: Calcium stearate which is also known as soap scum is insoluble in water.
Correct answer: Calcium salt of stearic acid- A. Neutral
- B. Negatively charged
- C. Positively charged
- D. Positively charged from inside and negatively charged from outside
Explanation: When sodium stearate comes in contact with grease particles, micelles are formed.
Correct answer: Negatively charged- A. Oxalyl urea
- B. Diazepam
- C. Veronal
- D. Eszopiclone
Explanation: Veronal is the trade name for a barbiturate drug and is used to induce sleep by suppressing the brain.
Correct answer: Oxalyl urea1231. Synthetic pheromones, which attract male gypsy moth are esters of which of the following acids?
- A. Acetic acid
- B. Hexanoic acid
- C. Decanoic acid
- D. Dodecanoic acid
Explanation: (Z)-7,8-epoxy-2-methyloctadecane is the synthetic pheromones, which attract male gypsy moth.
Correct answer: Acetic acid- A. Cotton seed oil
- B. Pea oil
- C. Coconut oil
- D. All of these
Explanation: Cottonseeds contains about 15 - 20 percent oil. Its naturally occurring gossypol toxin protects it from insect by changing its giving it…
Correct answer: Cotton seed oil- A. Barbituric acid
- B. Barbital
- C. Malonic ester
- D. Parabanic acid
Explanation: Malonic ester is used in the synthesis of barbiturates, which are a class of sedative and tranquilizer medications.
Correct answer: Malonic ester- A. Disinfectant
- B. Chemosterilant
- C. Tranquillisers
- D. Plant growth hannones
Explanation: Terpeniol and chloroxylenol are the compounds of disinfectant class that inactivate or destroy microorganisms.
Correct answer: Disinfectant1235. Benzidineis are:
- A. Analgesic
- B. Antiallergic
- C. Antidepressant
- D. None
Explanation: Benzidineis are antidepressants that can help relieve symptoms of depression, anxiety disorders, social anxiety disorder etc.
Correct answer: Antidepressant- A. -NO2
- B. -SO3OH
- C. -OH
- D. -NH2
Explanation: Basic dyes such as Methylene Blue, Crystal Violet have -NH2 group. These are very powerfull dyes and used to colour wool, silk, cotton etc.
Correct answer: -NH2- A. Cl2
- B. I2
- C. SO2
- D. Br2
Explanation: Commonly used inorganic antiseptics are Cl2, I2 and SO2
Correct answer: Br2- A. Luminal
- B. Salol
- C. Catechol
- D. Phenol
Explanation: Salol, catechol and phenol are used as antiseptic. Luminal is used to treat anxiety and sleep disorders so it works as hypotonic drug.
Correct answer: Luminal- A. N2O4 + acrylic rubber
- B. N2O4 + UDMH
- C. Polybutadiene + ammonium perchlorat
- D. Nitroglycerine + nitrocellulose
Explanation: Represents liquid propellants commonly used in rocket engines. This combination consists of nitrogen tetroxide (N2O4) as the oxidizer and…
Correct answer: N2O4 + UDMH- A. Azo dyes
- B. Phthalein dyes
- C. Anthrauinone dyes
- D. Triphenylmethane dyes
Explanation: Malachite green and rosaniline belong to the class of triphenylmethane dyes.
Correct answer: Triphenylmethane dyes