The vitamin whose active form, retinol, is essential for vision is: MCQ with Answer and Explanation

Explanation:
Relaxin is a peptide hormone produced by the corpus luteum and the placenta during pregnancy. Its primary roles are to relax the smooth muscles of the uterus (inhibiting contractions to maintain pregnancy) and to soften and increase the flexibility of the connective tissues in the pelvis, specifically the pelvic ligaments and the pubic symphysis. This relaxation and widening of the pelvic joints facilitate the passage of the baby through the birth canal during delivery.

Explanation:
Typhoid fever is a life-threatening systemic infection caused by the bacterium Salmonella typhi. It is transmitted through contaminated food and water. Symptoms include sustained high fever, headache, abdominal pain, and sometimes a rash. The Widal test is a common diagnostic test for typhoid. S. pneumoniae causes pneumonia, and V. cholerae causes cholera.

Explanation:
The appendix is considered vestigial (reduced and non-essential), but recent studies suggest it may have a minor immune function or serve as a reservoir for gut bacteria. So R is not entirely true (it may have a function). Thus, A is true but R is false (no function is an oversimplification).