What is true of deuterostomes?

Options

A. Presence of schizocoel
B. Nonformation of anus from blastopore
C. Coelum lined by mesoderm on both sides
D. Absence of false coelom.

Answer

### Step-by-Step Solution:

1. **Understanding Deuterostomes**: Deuterostomes are a group of animals characterized by their embryonic development. In these organisms, the first opening that forms during embryonic development becomes the anus, while the mouth develops from a second opening.

2. **Analyzing the Options**:
- **Option 1: Presence of Schizocoel**: Schizocoel refers to a type of coelom formation where the coelom develops from the splitting of mesodermal tissue. This is not true for deuterostomes, as they do not exhibit this type of coelom formation.
- **Option 2: Non-formation of anus from the blastopore**: This statement is incorrect. In deuterostomes, the blastopore does indeed develop into the anus, so this option is false.
- **Option 3: Coelom lined by mesoderm on both sides**: This statement is also incorrect. In deuterostomes, the coelom is not formed by the mesoderm on both sides; rather, it is formed from the archenteron.
- **Option 4: Absence of the false coelom**: This option is true. Deuterostomes do not have a false coelom (pseudocoelom); instead, they possess a true coelom that is fully lined by mesoderm.

3. **Conclusion**: Based on the analysis of the options, the only true statement about deuterostomes is the absence of the false coelom.

### Final Answer:
The correct statement about deuterostomes is that they have an absence of the false coelom.

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