NEET Practice Questions (MCQs) with Answers & Solutions

Energy is lost at each trophic level primarily in the form of heat due to metabolic processes. As organisms consume food and convert it into energy, a significant portion is lost as heat. This concept is based on the second law of thermodynamics, which states that energy transfer is not 100% efficient and that some energy is always lost as heat.

Modern sources of phosphorus that lead to eutrophication include detergents. Detergents often contain phosphates, which, when they enter water bodies through domestic wastewater, can result in the overgrowth of algae and subsequent eutrophication.

Mycorrhizae are symbiotic associations between fungi and plant roots that enhance the absorption of phosphorus. The fungi extend the root system's reach, allowing plants to access phosphorus more efficiently from the soil.

Crassulacean Acid Metabolism (CAM) is a specific adaptation found in xerophytes which allows them to fix CO2 at night, reducing water loss during the day. Other cycles like TCA, Hatch-Slack (C4), and C3 are not exclusive to xerophytes.

In Crassulacean Acid Metabolism (CAM) plants, CO2 absorption occurs during the night. This is because CAM plants open their stomata at night to minimize water loss in arid conditions and take in CO2, which is then fixed into organic acids for use during the day.

In ecology, the term 'ecosystem' refers to a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. Hence, the correct match for Ecology (X) is Ecosystem.

The size of a population in any particular area is influenced by multiple factors, including the availability of food, predation, and environmental pressure. All three factors interact to determine how a population grows or shrinks over time. Therefore, the correct answer is 'All three'.