In birds, which muscle is well developed ?

Options

A. Alary
B. Biceps
C. Gastroconemius
D. Pectoralis major

Answer

To determine which muscle is well-developed in birds, let's analyze the options provided:

1. **Allergy**: This muscle is not found in birds; it is associated with cockroaches. Therefore, this option is incorrect.

2. **Biceps**: While biceps are present in birds, they are not the primary muscles used for flight and are not well-developed in comparison to other muscles. Thus, this option is also incorrect.

3. **Gastrocnemius**: This muscle is located at the back of the legs and is responsible for leg movement. However, birds do not rely heavily on strong legs for their primary mode of locomotion (flying). Therefore, this option is incorrect as well.

4. **Pectoralis Major**: This muscle is located in the breast area of birds and is crucial for flight. It is well-developed and provides the necessary power stroke for birds to flap their wings and achieve lift. This makes it the correct answer.

**Final Answer**: The well-developed muscle in birds is the **Pectoralis Major**.