All Free Everyday Science MCQs with Answers

971. Which triplet in DNA codes for valine ?

• A. CTT
• B. AGU
• C. CAT
• D. AAT
• E. None of these

Explanation: Valine is coded by the mRNA codons GUU, GUC, GUA and GUG, corresponding to GTT, GTC, GTA and GTG on the DNA coding strand. None of the listed triplets is a valine codon.

972. Sensitive layer of the eye is?

• A. Choriods
• B. Sclerotic
• C. Retina
• D. Cornea
• E. None of these

Explanation: The retina is the light-sensitive layer containing rods and cones, which convert light into nerve signals. The cornea mainly focuses incoming light, while the sclera and choroid form protective and vascular layers.

973. The name of the common mineral salt present in sweat is ?

• A. Calcium Oxalate
• B. Potassium Sulphate
• C. Sodium Chloride
• D. Iron Sulphate
• E. None of these

Explanation: Sweat contains water and dissolved salts, especially sodium chloride, which accounts for its salty taste. Calcium oxalate and iron sulphate are not the common mineral salts of sweat.

974. Person with following blood group are considered to be universal recipient ?

• A. A+
• B. B+
• C. AB+
• D. O+
• E. None of these

Explanation: AB-positive blood is considered the universal recipient for red-cell transfusions because it has A and B antigens and Rh-positive status, but lacks anti-A and anti-B antibodies in its plasma. Compatibility testing is still required in practice.

975. The famous book; Al - Qanun was written by the Muslim scientist ?

• A. Jabar bin Hayyan
• B. Zakariya Al - Razi
• C. Abu Ali Sina
• D. Abdul Qasim Majreeti

Explanation: Al-Qanun fi al-Tibb, known in English as The Canon of Medicine, was written by Abu Ali Sina, or Avicenna. It was a major medical reference for centuries in both the Muslim world and Europe.

976. Humming bird belongs to a category called ?

• A. Ectotherm
• B. Endotherm
• C. Exotherm
• D. Heterotherm.

Explanation: Hummingbirds are endotherms because they generate and regulate their body heat internally through metabolism. Ectotherms depend mainly on environmental heat, while heterothermy is a variable-temperature strategy rather than the standard classification here.

977. What is bacteria that helps make yogurt ?

• A. Escherichia Coli
• B. Staphylococcus aureus
• C. Lactobacillus
• D. All of these.Physics

Explanation: Lactobacillus converts lactose in milk into lactic acid, lowering the pH and causing milk proteins to form yogurt. Escherichia coli and Staphylococcus aureus are not the usual yogurt-making bacteria.

978. What is the name of bacteria that causes Lyme Disease.

• A. Escherichia Coli
• B. Staphylococus aureus
• C. Borrelia burgdorferi
• D. None of these

Explanation: Lyme disease is caused mainly by Borrelia burgdorferi, a spiral-shaped bacterium transmitted by infected Ixodes ticks. The other listed bacteria cause different infections.

979. What are the components of Balance Diet?

• A. Carbohydrates+Fats
• B. Proteins+Water
• C. Vitamins+Minerals
• D. All of these

Explanation: A balanced diet includes carbohydrates, proteins, fats, vitamins, minerals and water in suitable proportions. Each listed pair is part of this overall set, so all of these is correct.

980. Examples of Monosaccharides are ___________.

• A. Glucose
• B. Galactose
• C. Fructose
• D. All of these

Explanation: Glucose, galactose and fructose are all monosaccharides, meaning they are single sugar units that cannot be hydrolysed into simpler carbohydrates. Therefore, all of these is correct.