The pale yellow colour of urine is due to the presence of the pigment Urochrome. Urochrome is a waste product formed from the breakdown of hemoglobin in red blood cells. It is produced when hemoglobin is metabolized into urobilin and then excreted through urine. The intensity of the yellow color can vary depending on hydration levels — darker urine indicates dehydration, while pale urine indicates proper hydration.

Other options (for context)

• Urophyll: No such pigment exists in human physiology.
• Chlorophyll: Green pigment found in plants, not in urine.
• Chloroplast: Cell organelle in plants where photosynthesis occurs, not a pigment.

Explanation: Bryology is the branch of botany that deals with the study of bryophytes, which include mosses and liverworts. These are small, non-vascular plants that typically grow in moist and shady environments.

Explanation: Shadows are formed when an opaque object comes in the path of light. Opaque objects do not allow light to pass through them, causing a dark region called a shadow to form on the opposite side. Transparent and translucent objects allow light to pass fully or partially, so they form faint or no shadows.

Explanation: In a parallel connection of resistances, the potential difference (voltage) across each resistor remains the same, while the current divides among the different branches according to their resistances. This property makes parallel circuits widely used in household electrical wiring.

Explanation: A transformer is an electrical device used to increase (step-up) or decrease (step-down) the voltage of alternating current (A.C.). It works on the principle of electromagnetic induction and functions only with A.C., not with D.C. A transformer consists of two coils—primary and secondary—wound around a soft iron core. The voltage ratio between these coils depends on the number of turns in each winding. Transformers are used in power transmission, distribution, and electronic devices to regulate voltage levels efficiently.

Explanation: During photosynthesis, green plants use sunlight to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). The oxygen gas released in this process comes specifically from the splitting of water molecules — a reaction known as photolysis of water, which occurs in the light-dependent reaction inside the chloroplasts.

Chemical equation:

6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O

The oxygen atoms in the released O₂ come entirely from the original water molecules, as demonstrated by isotopic experiments using heavy oxygen (O¹⁸) tracers.

Explanation: The full form of GPS is Global Positioning System. It is a satellite-based navigation system that provides accurate information about the location, speed, and time anywhere on Earth. Developed by the U.S. Department of Defense, GPS uses a network of at least 24 satellites orbiting the Earth. It is widely used in navigation, mapping, military operations, aviation, and smartphone tracking applications.

Explanation: Chikungunya is a viral disease caused by the Chikungunya virus, which belongs to the Togaviridae family. It is transmitted to humans through the bite of infected Aedes aegypti and Aedes albopictus mosquitoes. The disease causes sudden fever, joint pain, headache, and rash. In contrast, cholera (caused by Vibrio cholerae), typhoid (by Salmonella typhi), and tuberculosis (by Mycobacterium tuberculosis) are all bacterial diseases.

Explanation: Internet is the odd one out because it is a global network, whereas Linux, Unix and Windows are operating systems.