Which characteristic of many different animal groups is associated with bilateral symmetry?

Options

A. Cephalization
B. Sessile life style
C. Autotrophy
D. Radial body plan

Answer

### Step-by-Step Solution:

1. **Understanding Bilateral Symmetry**:
- Bilateral symmetry refers to a body plan in which the left and right sides of an organism are mirror images of each other. This means that if you were to divide the organism down the middle, both halves would be identical in shape and structure.

2. **Identifying Characteristics Associated with Bilateral Symmetry**:
- One of the key characteristics associated with bilateral symmetry is **cephalization**, which is the development of a head region where sensory organs and nerve tissues are concentrated. This is often seen in more complex organisms.

3. **Evaluating the Options**:
- The question mentions several options related to animal characteristics:
- **Cephalization**: This is indeed associated with bilateral symmetry as it involves the division of the brain into two hemispheres, which can be seen as a reflection of bilateral symmetry.
- **Sashile Lifestyle**: This refers to a non-motile lifestyle, which does not necessarily exhibit bilateral symmetry.
- **Autotropic**: This term describes organisms that produce their own food, which is not directly related to body symmetry.
- **Radial Body Plan**: This is a different type of symmetry where organisms can be divided into similar halves by multiple planes, which does not correspond to bilateral symmetry.

4. **Conclusion**:
- Based on the evaluation, the characteristic associated with bilateral symmetry is **cephalization**. Therefore, the correct answer to the question is **cephalization**.