Which of the following is an age-related bone disorder characterized by decreased bone mass and increased chances of fracture ?

Options

A. Osteoarthritis
B. Osteoporosis
C. Muscular dystrophy
D. Myasthenia gravis

Answer

To solve the question regarding the age-related bone disorder characterized by decreased bone mass and increased chances of fracture, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for an age-related bone disorder that leads to decreased bone mass and a higher risk of fractures.

2. **Evaluate the Options**:
- **Option 1: Osteoarthritis**: This is primarily a joint disorder characterized by the degeneration of cartilage. It does not primarily affect bone mass; instead, it affects the cartilage around the joints. Therefore, it is not the correct answer.

- **Option 2: Osteoporosis**: This is a well-known age-related bone disorder where there is a significant decrease in bone mass, leading to an increased risk of fractures. This condition is often associated with a deficiency in calcium and vitamin D, particularly in older adults. This option fits the criteria given in the question.

- **Option 3: Muscular Dystrophy**: This is a group of genetic disorders that cause muscle weakness and loss of muscle mass. It does not primarily affect bone mass or increase fracture risk directly, so it is not the correct answer.

- **Option 4: Myasthenia Gravis**: This is an autoimmune disorder that affects the communication between nerves and muscles, leading to muscle weakness. Similar to muscular dystrophy, it does not decrease bone mass or increase fracture risk, making it incorrect.

3. **Conclusion**: After evaluating all the options, it is clear that the correct answer is **Option 2: Osteoporosis**, as it is the only condition that is characterized by decreased bone mass and increased chances of fracture.

### Final Answer:
The age-related bone disorder characterized by decreased bone mass and increased chances of fracture is **Osteoporosis**.

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