Which one of the following organisms bears hollow and pneumatic long bones ?

The correct option is Neophron.

Step-by-step Explanation:

1. Understanding Pneumatic Bones:
Pneumatic bones are long bones that are hollow and contain air-filled cavities instead of bone marrow. This structural feature is a key evolutionary adaptation in birds (class Aves) that significantly reduces their body weight, making it easier for them to fly while maintaining the strength of their skeleton.

2. Analyzing the Organisms:
- Neophron (Egyptian vulture): It belongs to the class Aves (birds). Since it is a bird, it possesses hollow and pneumatic long bones to adapt to aerial locomotion.
- Hemidactylus (wall lizard): It belongs to the class Reptilia (reptiles). Reptiles do not have pneumatic bones; instead, their bones are typically solid and contain bone marrow.
- Macropus (kangaroo): It belongs to the class Mammalia (mammals). Mammals have heavy, solid bones filled with bone marrow to support their body weight on land.
- Ornithorhynchus (platypus): It is an egg-laying mammal (monotreme) belonging to the class Mammalia and does not have pneumatic bones.

Therefore, only Neophron possesses the characteristic of having hollow and pneumatic long bones.