Which of the following statements regarding the estimates of number of species found on earth is not correct ?
(a) Total number of species present on earth are considered to be about 7 million as estimated by Robert May.
(b) Plants constitute more than 70% of all the species recorded, whereas animals constitute less than 22% of the total number of species.
(c) Insects constitute more than 70% of all the animal species.
(d) None of these

Options

A. Total number of species present on earth are considered to be about 7 million as estimated by Robert May.
B. Plants constitute more than `70%` of all the species recorded, whereas animals constitute less than `22%` of the total number of species.
C. Insects constitute more than `70%` of all the animal species.
D. None of these

Explanation

To determine which statement regarding the estimates of the number of species found on Earth is not correct, we will analyze each option provided in the question:

1. **Statement A**: "Total number of species present on earth are considered to be about 7 million as estimated by Robert May."
- This statement is correct. Robert May estimated that there are approximately 7 million species on Earth.

2. **Statement B**: "Plants constitute more than 70% of all the species recorded, whereas animals constitute less than 22% of the total number of species."
- This statement is incorrect. In reality, animals constitute a larger percentage of recorded species compared to plants. It is estimated that animals make up about 70% of the species, while plants constitute less than 30%.

3. **Statement C**: "Insects constitute more than 70% of all the animal species."
- This statement is correct. Insects are indeed estimated to make up more than 70% of all animal species.

4. **Statement D**: "None of these."
- This statement implies that all previous statements are correct, which is not the case since we have identified Statement B as incorrect.

Based on the analysis, the statement that is not correct is **Statement B**.

### Final Answer:
The statement that is not correct is **(b)**: "Plants constitute more than 70% of all the species recorded, whereas animals constitute less than 22% of the total number of species."

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