Rickets in children is characterized by: MCQ with Answer and Explanation

Explanation:
The pancreas is a mixed gland; its exocrine part secretes digestive enzymes (trypsin, lipase, amylase), and its endocrine part (Islets of Langerhans) secretes hormones (insulin, glucagon). The liver continuously secretes bile, but bile does not contain digestive enzymes; it contains bile salts that emulsify fats. The gall bladder stores and concentrates this bile before releasing it into the duodenum. Thus, statements 1 and 3 are correct.

Explanation:
Azolla is an aquatic fern that harbors the nitrogen-fixing cyanobacterium Anabaena azollae in its leaf cavities. It is extensively used as a biofertilizer in rice paddies, adding organic nitrogen. Rhizobium fixes nitrogen in legume roots, Azotobacter is free-living in soil, mycorrhiza is a fungal association enhancing phosphorus uptake. Azolla multiplies rapidly and improves soil fertility.

Explanation:
The midbrain (mesencephalon) is the uppermost part of the brainstem. Its dorsal surface features four rounded elevations called the corpora quadrigemina (meaning 'four bodies'). These consist of two upper, larger swellings called the superior colliculi, which are reflex centers for visual movements (like tracking moving objects), and two lower, smaller swellings called the inferior colliculi, which are part of the auditory pathway and relay sound information to the thalamus.