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Question 3854

Acupuncture is a medical system of treatment in which:

Aherbs are used to relieve pain

Bneedles are inserted into particular parts of the body to relieve pain

Csurgery is done to relieve pain

Dnone of these

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B. needles are inserted into particular parts of the body to relieve painExplanation: Acupuncture is an ancient form of traditional Chinese medicine that involves the insertion of very thin needles through the skin at specific points, called acupoints. It is based on the concept of balancing the flow of life energy (Qi or Chi) through pathways in the body known as meridians. When these energy flows are blocked or imbalanced, it can cause illness or pain. By stimulating specific acupoints, acupuncture is believed to restore the normal energy flow and help the body heal itself. It is commonly used to treat: Chronic pain (e.g., back, neck, and joint pain) Migraines and headaches Arthritis and muscle stiffness Stress and anxiety Scientific View: Modern research suggests that acupuncture may stimulate nerves, muscles, and connective tissue, boosting the body’s natural painkillers (endorphins).

Question 3853

SA-node of mammalian heart is known as :

AAutoregulator

BPace-maker

CTime controller

DBeat regulator

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B. Pace-makerExplanation: The Sinoatrial (SA) node is a specialized group of modified cardiac muscle fibers located in the right atrium of the heart, near the opening of the superior vena cava. It generates electrical impulses (action potentials) that initiate each heartbeat. Therefore, it is known as the natural pacemaker of the heart. The impulses from the SA node spread across the atria, causing them to contract, and are then transmitted to the Atrioventricular (AV) node, Bundle of His, and Purkinje fibers to coordinate ventricular contraction. Normal rate of SA node firing: ~70–75 impulses per minute (in a healthy adult at rest). In case of SA node failure: Artificial pacemakers are implanted to maintain normal rhythm.

Question 3823

The element used for vulcanizing rubber is:

Asulphur

Bbromine

Csilicon

Dphosphorus

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A. sulphurExplanation: Sulphur is used in the process of vulcanization of rubber. During vulcanization, sulphur forms cross-links between the rubber molecules, improving elasticity, strength, and resistance to heat and wear. This makes natural rubber more durable and suitable for industrial use.

Question 3822

Lens is made up of:

Apyrex glass

Bflint glass

Cordinary glass

Dcobalt glass

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B. flint glassExplanation: A lens is generally made of flint glass, which contains lead oxide. Flint glass has a higher refractive index than ordinary glass, allowing it to bend light more effectively. This property makes it ideal for manufacturing optical instruments such as lenses and prisms.

Question 3821

The phenomenon of light associated with the appearance of the blue Colour of the sky is:

Ainterference

Breflection

Crefraction

Dscattering

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D. scatteringExplanation: The blue colour of the sky is due to the scattering of sunlight by molecules and small particles in the Earth's atmosphere. Shorter wavelengths of light (blue and violet) are scattered more than longer wavelengths (red and yellow). Since our eyes are more sensitive to blue light, the sky appears blue.

Question 3820

'Mirage' is an example of:

Arefraction of light only

Btotal internal reflection of light only

Crefraction and total internal reflection of light

Ddispersion of light only

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C. refraction and total internal reflection of lightExplanation: A mirage is an optical illusion caused by both refraction and total internal reflection of light. It occurs when light rays bend due to temperature variations in air layers near the ground, creating the illusion of water or a reflected image on hot surfaces like roads or deserts.

Question 3819

Which part is modified as the tusk of elephant?

Acanine

Bpremolar

Csecond incisor

Dmolar

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C. second incisorExplanation: The tusks of elephants are actually modified second upper incisors. They are made primarily of dentine, commonly known as ivory, and covered by a thin layer of enamel at the tip (which wears off with time). Tusks grow continuously throughout the elephant’s life and are used for digging, lifting objects, stripping bark, defense, and dominance displays. Note: Both male and female African elephants have tusks, whereas in Asian elephants, tusks are generally present only in males. Composition: Tusks are composed of dentine (ivory) with fine concentric growth lines, and they grow from sockets in the skull.

Question 3818

Which amongst the following is the largest mammal?

Aelephant

Bwhale

Cdinosaur

Drhinoceros

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B. whaleExplanation: The blue whale (Balaenoptera musculus) holds the record as the largest mammal and the largest living organism on Earth. Adult blue whales can reach lengths of up to 30 meters (98 feet) and weigh over 180 tons. Despite their size, they feed mainly on small shrimp-like creatures called krill, filtering them through their baleen plates. Whales are warm-blooded, breathe air through blowholes, and give birth to live young — all key mammalian traits. Comparison: Blue whale (largest mammal): up to 30 m long, ~180 tons African elephant (largest land mammal): up to 4 m tall, ~6 tons Rhinoceros: up to 2 m tall, ~2 tons

Question 3817

Which amongst the following is the largest endocrine gland in the body?

AThyroid

BParathyroid

CAdrenal

DPituitary

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A. ThyroidExplanation: The thyroid gland is the largest endocrine gland in the body. It is a butterfly-shaped gland situated in the neck region, just below the larynx. It secretes the hormones thyroxine (T₄) and triiodothyronine (T₃), which control metabolism, growth, and energy utilization. The thyroid also produces calcitonin, which helps regulate calcium levels in the blood. Functions of the Thyroid Gland: Regulates metabolic rate (BMR) Influences growth and development Maintains body temperature and energy balance Regulates calcium metabolism via calcitonin Disorders: Hypothyroidism: Leads to goitre, myxedema, or cretinism Hyperthyroidism: Leads to weight loss, anxiety, and increased heart rate

Question 3816

The pH of human blood is:

A7.2

B7.8

C6.6

D7.4

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D. 7.4Explanation: Human blood is maintained at a slightly alkaline pH of 7.4 (range 7.35–7.45). This balance is vital for the proper functioning of enzymes and biochemical reactions in the body. The buffer systems in blood — primarily the bicarbonate buffer system (H₂CO₃ / HCO₃⁻) — help maintain this stable pH. A small deviation from this range can lead to severe physiological disturbances. Imbalances: Acidosis: pH below 7.35 — causes drowsiness, confusion, and respiratory distress. Alkalosis: pH above 7.45 — causes muscle twitching, irritability, and convulsions.

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Science

Acupuncture is a medical system of treatment in which:

SA-node of mammalian heart is known as :

The element used for vulcanizing rubber is:

Lens is made up of:

The phenomenon of light associated with the appearance of the blue Colour of the sky is:

'Mirage' is an example of:

Which part is modified as the tusk of elephant?

Which amongst the following is the largest mammal?

Which amongst the following is the largest endocrine gland in the body?

The pH of human blood is:

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