The disease 'rabies' is caused by: MCQ with Answer and Explanation

Explanation:
The chorion is the outermost membrane surrounding the embryo. It forms chorionic villi that interdigitate with maternal uterine tissue to form the placenta, facilitating nutrient and gas exchange. The amnion surrounds the embryo, forming a fluid-filled cavity. The yolk sac is involved in early nutrition, allantois forms part of the umbilical cord. The chorion is derived from trophoblast and extraembryonic mesoderm.

Explanation:
HIV is a retrovirus with two copies of single-stranded RNA as its genome. It uses reverse transcriptase to convert RNA into DNA upon infection. Double-stranded DNA is typical of many organisms. Single-stranded DNA viruses exist (e.g., parvovirus). Double-stranded RNA viruses include rotavirus. The viral RNA genome enables integration into host DNA via a DNA intermediate.

Explanation:
The Bohr effect describes how an increase in pCO2 or a decrease in pH (increase in H+) reduces hemoglobin's affinity for oxygen, shifting the oxygen dissociation curve to the right and promoting oxygen unloading. Conversely, in the lungs, where pCO2 is low and pH is relatively higher (more alkaline), the Bohr effect works in reverse: hemoglobin's affinity for oxygen increases, facilitating the loading (binding) of oxygen to hemoglobin. The Haldane effect describes the reciprocal relationship for CO2 transport.