Vitamin D is essential for calcium absorption and bone health. Its deficiency leads to rickets in children, a condition characterized by soft and weak bones, leading to deformities such as bowed legs. In adults, vitamin D deficiency can cause osteomalacia, which results in bone pain and muscle weakness. Vitamin D is obtained from sunlight exposure and certain foods. Scurvy is caused by vitamin C deficiency, and night blindness is due to vitamin A deficiency. Fibrosis is unrelated. Thus, rickets is the correct answer. This highlights the importance of balanced nutrition and sunlight exposure for maintaining healthy bones.

Kirthar range spans Sindh and Balochistan, so both A & B correct.

This UN day is observed on 17 June to raise awareness about desertification and drought issues worldwide.

Zahid Hussain was the first Governor of the State Bank of Pakistan when it was established in 1948. The State Bank serves as the central bank of the country and is responsible for monetary policy, currency issuance, and financial stability. As the first governor, Zahid Hussain played a crucial role in setting up the banking system of the newly independent Pakistan. His leadership helped establish financial institutions and regulatory frameworks. Other options include later officials or unrelated figures. Shamshad Akhtar served much later, while Malik Ghulam Muhammad was a political figure. Thus, Zahid Hussain is the correct answer, marking an important milestone in Pakistan’s economic history.

Pepsinogen is an inactive precursor, or zymogen, secreted by the gastric glands in the stomach lining. It is converted into its active form, pepsin, in the presence of hydrochloric acid (HCl). This acidic environment triggers the activation process. Pepsin is a proteolytic enzyme that begins the digestion of proteins by breaking them down into smaller peptides. This process is essential for further digestion and absorption in the small intestine. The conversion of pepsinogen into pepsin is a protective mechanism. If pepsin were active inside the cells that produce it, it could digest the stomach lining itself. By secreting it in an inactive form, the body prevents self-damage. Other options are incorrect: “enzyme” is too general, proteins are the substrate, and amylase digests carbohydrates. Thus, pepsin is the correct answer. This concept is important for understanding enzyme activation and digestive physiology, commonly tested in exams.