General Science & Technology

An abacus is a manual calculating tool used for arithmetic operations. Unlike a computer or book, it performs mathematical calculations through bead manipulation. Japanese (soroban) and Chinese (suanpan) cultures have used it for centuries.

The zodiac is a belt-shaped region in the sky through which both the sun and moon appear to move. It's divided into 12 equal parts, each named after constellations. The apparent paths of both celestial bodies lie along this ecliptic region.

Yoga is a holistic practice that integrates physical postures (asanas), dietary control, and meditation (dhyana) for maintaining physical and mental well-being. All three components are essential aspects of yogic science for body maintenance.

The abdomen (belly region) is the body cavity located below the chest (thorax). It contains digestive organs and is separated from the chest by the diaphragm. The nose, throat, and liver are either above or within the abdominal region.

Acid rain forms when sulfur dioxide (SO2) and nitrogen oxides (NOx) from industrial emissions react with water vapor in the atmosphere. Carbon dioxide contributes to general rain acidity but is not the primary cause of acid rain phenomenon.

The Y chromosome is the sex-determining chromosome in humans. Females have XX chromosomes while males have XY chromosomes. Presence of the Y chromosome determines male sexual characteristics during development.

Zero represents 'nothing' or the absence of quantity in mathematics. It's a placeholder value indicating null or empty quantity. Unlike counting or calculating which are operations, zero is a concept representing the null value itself.

An aerial (antenna) is specifically designed to capture electromagnetic waves of particular frequencies broadcast by radio or TV stations. It converts these waves into electrical signals. Wires conduct signals and modems modulate digital data, but don't capture broadcast waves.

The zodiac belt is divided into 12 equal parts, each corresponding to a zodiac sign (Aries, Taurus, etc.). This division corresponds to the apparent path of the sun through 12 constellations over the course of a year.

Zenith is the point in the sky directly overhead an observer. It's the highest point from the observer's perspective on the celestial sphere. The atmosphere contains air, Earth is the planet, and sphere is a geometric shape - none refer to this specific point.

Yeast is a unicellular fungus used in baking and brewing. Unlike crows (animals), viruses (non-cellular), or bacteria (prokaryotes), yeast is a eukaryotic fungal organism. It reproduces by budding and is classified under Kingdom Fungi.

Males have one X chromosome and one Y chromosome (XY sex determination). The X chromosome comes from the mother and the Y chromosome from the father. Females have two X chromosomes (XX).

Air is a homogeneous mixture of several gases, primarily nitrogen (about 78%), oxygen (about 21%), and small amounts of argon, carbon dioxide, and other gases. It is not a pure substance or just 'gas'.

White Blood Cells (WBCs) are colorless.

Among the given options, 'Network of computers' is the closest to describing WWW, though this is imprecise. WWW (World Wide Web) is a system of interlinked hypertext documents accessed over the internet. The options are poorly framed - WHO and 'UN organization' are irrelevant.

Anemia is a condition characterized by a deficiency of red blood cells or hemoglobin in the blood. Iron is a crucial component of hemoglobin, which carries oxygen. Without sufficient iron, the body cannot produce enough healthy red blood cells.

Analgesics are medications specifically designed to relieve pain by acting on the nervous system to suppress pain signals. The term comes from Greek 'an' (without) and 'algos' (pain). Common analgesics include paracetamol, ibuprofen, and aspirin.