A young woman comes to the emergency room with a vertebral compression fracture. Radiographs of the spine indicate generalized demineralization. She is vegetarian, does not smoke or drink alcohol, has normal plasma potassium concentration of 5.4 mEq/L, sodium concentration of 136 mEq/L, plasma calcium concentration is 7.0 mg/dL. Her vitamin D3 value is several times greater than normal, although her 1,25-dihydroxycholecalciferol concentration is at the lower limit of detectability. She has been in renal failure for the last 5 years and undergoes hemodialysis three times each week. What is the cause of her low 1,25-dihydroxycholecalciferol level?

#Question id: 1706

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements is the best example of a primary lymphoid organ?

#Question id: 28449

#Unit 5. Developmental Biology

In C. elegans during embryogenesis, an anchor cell and 6 hypodermal vulval precursor cells (VPCs) get involved in forming the vulva. Which of the following statement is incorrect about  VPCs?

#Question id: 29537

#Unit 6. System Physiology – Plant

Polygalacturonases (PG) secreted by the fungal hyphae interact with plant cell by

#Question id: 1371

#Unit 4. Cell Communication and Cell Signaling

A researcher was studying a protein ‘A’ which has been observed to move across cells when an extracellular electrical stimulus is provided. An artificial peptide ‘Z’ was prepared which resembles the structure of pannexins and competitively inhibits pannexon formation. Which one of the following statements will best explain the fate of protein ‘A’ if, the cells are treated with peptide ‘Z’ and then, electrical stimulus is provided.

#Question id: 23703

#Unit 13. Methods in Biology