Explanation: The processes that add carbon dioxide (CO₂) to the carbon cycle on Earth are:

• 1. Volcanic action: Volcanic eruptions release large amounts of CO₂ and other gases from the Earth’s interior into the atmosphere.
• 2. Respiration: All living organisms release CO₂ as a by-product of breaking down glucose during cellular respiration.
• 4. Decay of organic matter: Decomposition of dead plants and animals by microbes produces CO₂ and methane (CH₄).

Photosynthesis (option 3), on the other hand, removes CO₂ from the atmosphere as plants use it to produce glucose and release oxygen.

Explanation: The age of a tree is determined by counting the annual growth rings (also called annual rings) visible in a cross-section of its trunk. Each ring consists of a light band (spring wood) and a dark band (autumn wood), representing one year of growth. The study of these rings to determine a tree’s age and past climate conditions is known as dendrochronology.

Explanation: The Bureau of Energy Efficiency (BEE) is an autonomous government agency set up by the Government of India under the Ministry of Power in 2002. It was established under the provisions of the Energy Conservation Act, 2001. The primary objective of BEE is to promote policies and programs that increase the efficiency of energy use in various sectors of the economy. BEE also develops energy efficiency standards and labeling programs for appliances and buildings, such as the star-rating system seen on electrical devices.