Number of known species of organisms on this earth is

Options

A. 5.0 million
B. 3.2 million
C. 1.7 million
D. 1.32 million

Answer

To determine the number of known species of organisms on Earth, we can follow these steps:

### Step 1: Understand the Question
The question asks for the number of known species of organisms on Earth. This includes all types of organisms, such as plants, animals, fungi, and microorganisms.

**Hint:** Focus on the definition of species and the context of biodiversity.

### Step 2: Analyze the Options
We have four options provided:
1. 5.0 million
2. 3.2 million
3. 1.7 million
4. 1.32 million

**Hint:** Look for the most commonly accepted scientific data regarding the number of known species.

### Step 3: Reference Scientific Data
Scientific research and data indicate that approximately 1.7 million species have been identified and classified. This number is widely accepted in the scientific community and is supported by various studies and databases.

**Hint:** Consider the reliability of sources, such as government publications or educational resources.

### Step 4: Eliminate Incorrect Options
- **5.0 million:** This number is too high compared to the accepted data.
- **3.2 million:** This is also higher than the commonly accepted figure.
- **1.32 million:** This number is lower than the known data.

**Hint:** Use the process of elimination to narrow down the options.

### Step 5: Confirm the Correct Answer
The only option that aligns with the scientific consensus is **1.7 million**. Therefore, the correct answer is option 3.

**Hint:** Always verify your answer with credible scientific sources or literature.

### Final Answer
The number of known species of organisms on Earth is approximately **1.7 million**.

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