What is the estimated amount of waste (in kg) generated by each person in an urban area every day?

Flow of energy in an ecosystem is always

What will be the amount of energy available to the organisms of the $2^{\text{nd}}$ trophic level of a food chain,if the energy available at the first trophic level is $10,000 \, J$?

List two man-made ecosystems.

You are advised to use eco-friendly appliances like refrigerators and $ACs$. Giving reasons,explain how these devices cause harm to the environment.

Green plants capture sunlight and convert it into which form of energy?