Nitrates are reduced back into nitrogen in the soil by a process called denitrification. This process is performed by bacteria like Pseudomonas denitrificans, etc.

The term "overdose" in the context of essential elements for plants suggests an excess or imbalance of nutrients, which can have negative effects on plant health. Among the options given:

(A) Nitrogen

Explanation: While all nutrients are essential for plant growth, an overdose or excessive application of nitrogen (option A) can lead to problems such as nutrient imbalance, environmental pollution, and increased susceptibility to certain diseases. Excessive nitrogen can cause rapid vegetative growth, but it may negatively impact other aspects of plant health, such as root development, flowering, and overall resilience.

Balanced nutrient management is crucial for optimal plant growth, and it's important to consider the specific requirements of each plant species and the soil conditions to avoid nutrient imbalances and potential negative effects on plant health.

Sleeping under a tree is not advisable at night, since photosynthesis does not occur, oxygen is not being produced by the trees. In addition to this, the trees continue respiring thereby causing the amount of carbon dioxide to be increased and the amount of oxygen to be reduced.

The different breeds mentioned—Gir, Sahiwal, and Lal Singhi—are associated with:

(A) Cow

Explanation:

Gir, Sahiwal, and Lal Singhi are breeds of cows (cattle). These breeds are known for their distinct characteristics, including milk production, adaptability to specific environments, and other traits that make them well-suited for various agricultural purposes. Therefore, the correct answer is (A) Cow.