General Science and Technology Fundamentals

The Trishul missile system was developed as a quick-reaction surface-to-air missile specifically for defending naval vessels against incoming anti-ship missiles. While India has land-based short-range SAMs, Trishul was primarily designed for naval point defense. Option A correctly identifies this primary purpose.

Astigmatism results from an irregularly shaped cornea (or sometimes lens) that refracts light unevenly, causing blurred or distorted vision at all distances. The cornea's surface should be spherical like a basketball, but in astigmatism it's more football-shaped.

Wernicke's area, located in the temporal lobe (usually left), is essential for language comprehension. Damage causes receptive aphasia - patients can speak fluently but produce nonsensical words and cannot understand spoken or written language. Broca's area handles speech production instead.

Visceral muscle is the correct anatomical term for smooth muscle - found in hollow organs (stomach, intestines, blood vessels, uterus). It's involuntary, non-striated, and controlled by the autonomic nervous system. Cardiac muscle is only in the heart, and skeletal muscle moves bones.

The brain is the central processing organ of the nervous system, receiving sensory input, coordinating responses, and enabling cognition. The circulatory system moves blood, respiratory handles gas exchange, and excretory removes waste. The brain contains neurons and glial cells that transmit electrical signals.

The lung is part of the respiratory system, exchanging oxygen and carbon dioxide. The circulatory system comprises the heart, blood vessels (arteries, veins, capillaries), and blood - which transport materials throughout the body. Lungs and heart work together but belong to different systems.

The small intestine (duodenum, jejunum, ileum) is the longest digestive tube section at about 6 meters (20 feet). Most nutrient absorption occurs here through villi and microvilli. The large intestine is about 1.5 meters, and the stomach is a J-shaped organ, not a tube.

The liver is the body's largest internal gland (1.4-1.6 kg), performing vital functions: bile production, detoxification, protein synthesis, glycogen storage. The thyroid and pituitary are much smaller endocrine glands. Kidneys filter blood but are excretory organs, not glands.

Epithelial tissue forms protective covering layers on body surfaces (skin epidermis), lines internal cavities and organs, and comprises glands. Cells are tightly packed with minimal extracellular matrix. Connective tissue binds structures, nervous tissue transmits signals, and muscle tissue contracts.

The sinoatrial (SA) node, located in the right atrium near the superior vena cava, is the heart's natural pacemaker. It spontaneously generates electrical impulses (~60-100 bpm) that initiate each heartbeat. The AV node delays impulses, and Purkinje fibers conduct signals to ventricles.

The hindbrain (rhombencephalon) comprises the cerebellum, pons, and medulla oblongata. The mesencephalon is the midbrain, and prosencephalon is the forebrain (cerebrum + diencephalon). These are developmental divisions of the brain.

Aqua fortis is Latin for 'strong water' and historically refers to nitric acid (HNO₃). Nitric acid is a strong corrosive acid, while nitrous oxide (N₂O) is a gas, and nitrogen (N₂) is an element.

Arboreal creatures are tree-dwelling animals. The term comes from the Latin 'arbor' meaning tree. Mountains, hills, and rivers are not the primary habitat of arboreal animals - they live in and among trees.

The mandible is the anatomical name for the lower jawbone in vertebrates. The occipital bone is at the back of the skull, and the cranium refers to the entire skull enclosing the brain.

Ruminating refers to the process of chewing cud - regurgitated food that ruminants like cows, sheep, and deer chew again to aid digestion. It's a multi-stage digestive process, not related to roaming or sleeping.

Hippopotamus comes from Greek 'hippos' meaning horse and 'potamos' meaning river. The name literally translates to 'river horse.' Rhinoceros means 'nose horn' in Greek, and regular horses are terrestrial, not river-dwelling.

Dichlorodiphenyltrichloroethane is commonly abbreviated as DDT, a well-known insecticide. The initials come from the first letters of each major component in its chemical name.

Vitamin B2 is riboflavin. Thiamine is B1, pyridoxine is B6, and cyanocobalamin is B12. Riboflavin comes from 'flavus' (yellow) due to its yellow color.

Sulphur (sulfur) was historically known as brimstone. The term appears in ancient texts and religious documents. Brimstone refers to the burning smell of sulfur, especially in volcanic areas.

Morphine is the white crystalline alkaloid derived from opium. It's the principal active ingredient in opium and is a potent pain reliever. Thebaine and codeine are also opium alkaloids, but 'opiates' is the general category, not a specific alkaloid.