Explanation: Sugarcane (Saccharum officinarum) is a tall, jointed, perennial grass belonging to the family Poaceae. It has thick stems rich in sucrose, which is extracted to produce sugar. The plant reproduces mainly through stem cuttings (vegetative propagation). Its structure and growth habit are similar to other grasses like maize and bamboo.

Explanation: Photosynthesis is the process by which green plants, algae, and some bacteria use sunlight to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). This process takes place in the chloroplasts of plant cells, which contain the green pigment chlorophyll that captures solar energy.

Chemical Equation:

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Thus, plants are known as autotrophs because they produce their own food using light energy — a process vital for sustaining all life on Earth.

Explanation: ELISA stands for Enzyme-linked immunosorbent assay. It is a biochemical test used to detect and measure antibodies, antigens, proteins, or hormones in a sample. The method relies on an enzyme-linked antigen or antibody and a color change to indicate a positive reaction.

Explanation: The main constituents of biogas are methane (CH₄) and carbon dioxide (CO₂). Biogas is produced through the anaerobic decomposition of organic matter such as animal dung and plant waste. Methane acts as the primary combustible component, making biogas an efficient and renewable source of energy.

The full form of LAN is Local Area Network. It is a network that connects computers and devices within a limited geographical area such as a home, office, school, or building. LANs enable data sharing, resource sharing (like printers or internet connections), and communication between connected devices. Common technologies used in LANs include Ethernet and Wi-Fi.

Other options (for context)

• Line Area Network: Incorrect — not a recognized networking term.
• Linear Area Network: Incorrect — there is no such standard network type.
• Land Area Network: Incorrect — misinterpretation of LAN abbreviation.

The Kyoto Protocol is an international agreement related to the environment, specifically aimed at reducing greenhouse gas emissions that contribute to global warming and climate change. It was adopted in Kyoto, Japan, in 1997 and came into force in 2005. The protocol set binding targets for developed countries to limit or reduce their carbon dioxide (CO₂) and other greenhouse gas emissions.

Other options (for context)

• Nuclear Power: Not the focus of the Kyoto Protocol; this relates to energy generation and atomic energy regulation.
• Trade: Covered under agreements like GATT and WTO, not the Kyoto Protocol.
• None of these: Incorrect — the Kyoto Protocol deals specifically with environmental protection.

Explanation: Mitochondria are double-membraned organelles found in almost all eukaryotic cells. They are known as the 'power house of the cell' because they generate adenosine triphosphate (ATP) through the process of cellular respiration. The inner membrane forms folds called cristae, which increase the surface area for enzyme activity related to energy production. Mitochondria also contain their own DNA and ribosomes, enabling them to produce some of their own proteins.

Key Reaction:

Glucose + Oxygen → Carbon dioxide + Water + ATP