Chordate animals have

Options

A. Solid spinal cord and brain
B. Ventral hollow nerve cord
C. Dorsal hollow nervous system
D. Ventral solid nervous system

Answer

**Step-by-Step Solution:**

1. **Understanding Chordates**: Chordates are a diverse group of animals that belong to the phylum Chordata. They are characterized by specific features that distinguish them from other animal groups.

2. **Identifying Key Characteristics**:
- **Notochord**: This is a flexible rod-like structure that provides support and is present in all chordates at some stage of their development.
- **Hollow Dorsal Nerve Cord**: This structure runs along the back (dorsal side) of the organism and is a key feature of chordates. It develops into the brain and spinal cord in vertebrates.
- **Pharyngeal Gill Slits**: These are openings that appear in the pharyngeal region and are involved in respiration or filter feeding. They are present during certain life stages of chordates.
- **Post-Anal Tail**: This is an extension of the body past the anal opening and is present in many chordates, providing mobility.

3. **Analyzing the Options**:
- The question likely provides multiple options regarding the characteristics of chordates. We need to identify which of these options correctly describe the features of chordates.
- For example, options may include "solid spinal cord and brain," "ventral hollow nerve cord," "dorsal hollow nerve cord," and "ventral solid nervous system."

4. **Evaluating Each Option**:
- **Solid Spinal Cord and Brain**: This is incorrect for chordates as they possess a hollow dorsal nerve cord.
- **Ventral Hollow Nerve Cord**: This is also incorrect since the nerve cord is located dorsally.
- **Dorsal Hollow Nerve Cord**: This is a correct characteristic of chordates.
- **Ventral Solid Nervous System**: This is incorrect as chordates do not have a ventral nervous system.

5. **Conclusion**: Based on the analysis, the correct characteristic of chordates is the "dorsal hollow nerve cord." Therefore, the answer would be the option that states this characteristic.