Invertebrate species are believed to make up close to what percentage of all animal species?

Options

A. `10%`
B. `30%`
C. `50%`
D. `90%`

Answer

To determine the percentage of invertebrate species among all animal species, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Classification of Animal Species**:
- Animals are broadly classified into two main groups: vertebrates (animals with a backbone) and invertebrates (animals without a backbone).

2. **Identify the Proportion of Vertebrates**:
- According to the information provided, vertebrates make up a smaller portion of the total animal species. It is stated that vertebrates constitute about 10% of all animal species.

3. **Calculate the Percentage of Invertebrates**:
- Since vertebrates account for 10% of all animal species, the remaining percentage must be invertebrates.
- Therefore, the percentage of invertebrates can be calculated as follows:
\[ \text{Percentage of Invertebrates} = 100\% - \text{Percentage of Vertebrates} \]
\[ \text{Percentage of Invertebrates} = 100\% - 10\% = 90\% \]

4. **Conclusion**:
- Invertebrate species are believed to make up close to 90% of all animal species.

### Final Answer:
Invertebrate species are believed to make up close to **90%** of all animal species.

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