Question

Which of the following statements is/are INCORRECT regarding the immune system of an adult human being when compared to a child?

• A. Thymus degenerates in old individuals
  resulting in a decreased production of thymosins
• B. The immune responses of old persons become weak
• C. The immunity of old person becomes weak
• D. Vaccination is mostly given in childhood as an immune response is weaker in children

Answer 1

Answer: (A), (B)

The correct options are
A Thymus degenerates in old individuals
resulting in a decreased production of thymosins
B The immune responses of old persons become weak

The thymus gland is a lobular structure located between the lungs behind sternum on the ventral side of the aorta. The thymus plays a major role in the development of the immune system.
Thymosins play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also promote the production of antibodies to provide humoral immunity.
the immune responses of old persons become weak because Thymus is degenerated in old individuals resulting in a decreased production of thymosins.
So, the correct option is 'Both A and B'.