Correct Option
The correct option is (c).
Explanation
The Earth is surrounded by a layer of gas known as the atmosphere. This mixture of gases sustains life by providing necessary elements for respiration and growth while shielding the planet from the harsh environment of space.Statement 1 is Incorrect: Oxygen is the gas essential for human respiration and is referred to as the "breath of life." Carbon dioxide is vital for plants during photosynthesis to produce food, but it is not the primary gas inhaled by humans for survival.
Statement 2 is Correct: Nitrogen is the most abundant gas in the atmosphere, constituting approximately 78% of its volume. It is a critical component of amino acids, proteins, and nucleic acids (DNA and RNA), making it essential for the growth and structure of all living organisms.
Statement 3 is Correct: The atmosphere protects life on Earth by absorbing harmful ultraviolet (UV) solar radiation, primarily through the ozone layer in the stratosphere. It also regulates temperature, preventing extreme heat during the day and excessive cooling at night.
Key Takeaway: The atmosphere is a life-sustaining shield where Nitrogen supports structural growth in organisms, Oxygen supports respiration, and the collective gaseous layer protects against harmful solar radiation.