Consider the following statements and choose the correct option :-
(i) Sun is the only source of energy for all ecosystem on earth
(ii) PAR is less than 50 percent in incident solar radiation

Options

A. only i is correct
B. only ii is correct
C. both i & ii are correct
D. both are incorrect

Answer

To solve the question regarding the statements about the sun and photosynthetically active radiation (PAR), let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Evaluate Statement (i)**: "Sun is the only source of energy for all ecosystems on earth."
- The sun is indeed the primary source of energy for nearly all ecosystems. It provides solar energy, which is harnessed by plants through photosynthesis. This energy is then transferred through the food chain as organisms consume plants and each other. Therefore, this statement is **correct**.

2. **Evaluate Statement (ii)**: "PAR is less than 50 percent in incident solar radiation."
- PAR, or Photosynthetically Active Radiation, refers to the portion of sunlight that plants can use for photosynthesis, typically within the wavelength range of 400 to 700 nanometers. It is known that PAR constitutes less than 50% of the total incident solar radiation that reaches the Earth's surface. Hence, this statement is also **correct**.

3. **Conclusion**: Since both statements (i) and (ii) are correct, the correct option is that both statements are true.

### Final Answer:
Both statements are correct.