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Question 2951

Nitrogen is an essential constituent of all:

ACarbohydrates

BFats

CProteins

DVitamins

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C. ProteinsExplanation: Proteins are complex organic compounds composed of smaller units called amino acids. Each amino acid contains an amino group (–NH₂), which contributes nitrogen to the molecular structure. This makes nitrogen an essential element in all proteins. Carbohydrates and fats lack nitrogen, while only some vitamins contain it.

Question 2950

Who discovered electromagnetic nature of light?

AYoung

BSnell

CNewton

DMaxwell

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D. MaxwellExplanation not yet available.

Question 2949

Persistence of vision is the principle behind:

ACamera

BBinocular

CCinema

DPeriscope

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C. CinemaExplanation not yet available.

Question 2948

Malaria is transmitted from one person to another by:

AAedes Mosquito

BCulex Mosquito

CAnopheles Mosquito

DAll of the above

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C. Anopheles MosquitoExplanation: Malaria is caused by the protozoan parasite Plasmodium (species such as *P. vivax*, *P. falciparum*, *P. malariae*, and *P. ovale*). It spreads through the bite of an infected female Anopheles mosquito. The mosquito injects sporozoites (infective stage of *Plasmodium*) into the human bloodstream. These parasites infect liver cells, multiply, and later invade red blood cells, causing symptoms like fever, chills, and

Question 2947

Cuscuta is a :

AParasite

BSaprophyte

CEpiphyte

DXerophyte

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A. ParasiteExplanation: Cuscuta, commonly known as dodder plant or amarbel, is a total stem parasite. It lacks chlorophyll and cannot perform photosynthesis. Instead, it attaches itself to the host plant using specialized structures called haustoria that penetrate the host’s vascular tissues to absorb nutrients and water. Cuscuta is usually seen twining around host plants such as lucerne, hedg

Question 2946

Which one of the following hormone is called "Emergency Hormone"?

AInsulin

BAdrenaline

CThyroxine

DVasopressin

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B. AdrenalineExplanation: Adrenaline (also known as epinephrine) is secreted by the adrenal medulla in response to stress, fear, anger, or excitement. It prepares the body for “fight or flight” by increasing heart rate, blood pressure, and glucose levels, and by dilating the air passages to supply more oxygen. Because it helps the body respond instantly to emergencies, it is called the “emergency hormone.”

Question 2944

The layer of the atmosphere in which Radio Waves are reflected back is called:

AExosphere

BIonosphere

CTroposphere

DStratosphere

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B. IonosphereExplanation not yet available.

Question 2793

The technique of 'DNA sequencing' was discovered by:

AH. G. Khorana

BWatson and Crick

CFrederick Sanger

DE. M. Southern

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B. Watson and CrickExplanation: The DNA sequencing technique was developed by Frederick Sanger in 1977. His method, known as the Sanger chain termination method, determines the nucleotide sequence of DNA using labeled dideoxynucleotides (ddNTPs) that terminate DNA chain elongation. This technique revolutionized molecular biology and became the foundation for genome sequencing projects such as the Human Genome Project.

Question 2776

Part of earth where life exist is known as:

ALithosphere

BHydrosphere

CAtmosphere

DBiosphere

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D. BiosphereExplanation: The biosphere is the global sum of all ecosystems — it encompasses every region of Earth where living organisms are found. It includes portions of the lithosphere (land), hydrosphere (water), and atmosphere (air) that support life. The biosphere extends from deep ocean trenches to the lower layers of the atmosphere where microorganisms can survive.

Question 2774

The motion of which particle through a metallic wire is called electric current?

AElectron

BPositron

CNeutron

DPhoton

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A. ElectronExplanation: The flow of electrons through a metallic wire constitutes an electric current. In metals, free electrons move from the negative terminal to the positive terminal of a power source, while the conventional direction of current is taken as opposite — from positive to negative.

Preparing your study space

Science

Nitrogen is an essential constituent of all:

Who discovered electromagnetic nature of light?

Persistence of vision is the principle behind:

Malaria is transmitted from one person to another by:

Cuscuta is a :

Which one of the following hormone is called "Emergency Hormone"?

The layer of the atmosphere in which Radio Waves are reflected back is called:

The technique of 'DNA sequencing' was discovered by:

Part of earth where life exist is known as:

The motion of which particle through a metallic wire is called electric current?

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