Productivity contributed by oceans is ______but area coverage is compartively ______

Options

A. High , less
B. Low , more
C. `10,71%`
D. `50%,71%`

Answer

To solve the question "Productivity contributed by oceans is ______ but area coverage is comparatively ______", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ocean Productivity**:
- Ocean productivity refers to the rate at which plants (primarily phytoplankton) produce organic compounds through photosynthesis. This is influenced by the availability of carbon dioxide (CO2) and nutrients in the water.

2. **Evaluating Ocean Productivity**:
- It is known that ocean productivity is significantly high due to the presence of a biological pump. This pump helps in the transfer of CO2 from the atmosphere to the deep ocean, where it is utilized by marine plants for photosynthesis.

3. **Comparing Area Coverage**:
- Although oceans cover a vast area of the Earth's surface (about 71%), the actual productivity per unit area is comparatively less than that of terrestrial ecosystems. This means that while oceans are extensive, the productivity per unit area is lower.

4. **Filling in the Blanks**:
- Based on the above understanding, we can conclude that the productivity contributed by oceans is "high" due to the biological pump and the deep ocean's capacity to support photosynthesis. However, the area coverage is "less" in terms of productivity per unit area when compared to land ecosystems.

5. **Final Answer**:
- Therefore, the complete statement is: "Productivity contributed by oceans is **high** but area coverage is comparatively **less**."