The disease caused by the human immunodeficiency virus (HIV) is: MCQ with Answer and Explanation

Explanation:
Bryophytes are non-vascular land plants that include mosses, liverworts, and hornworts. Funaria is a common moss and a classic example of a bryophyte. Spirogyra is a green alga, ferns are pteridophytes (vascular cryptogams), and Pinus is a gymnosperm.

Explanation:
Approximately 97% of O₂ is transported bound to hemoglobin (as oxyhemoglobin), while only 3% is dissolved in plasma. Each hemoglobin molecule can bind four O₂ molecules cooperatively. CO₂ is mainly transported as bicarbonate (70%), carbaminohemoglobin (23%), and dissolved (7%). The affinity of hemoglobin for O₂ is influenced by pH, CO₂, and temperature (Bohr effect).

Explanation:
Intrinsic factor, a glycoprotein secreted by gastric parietal cells, binds to vitamin B₁₂ and facilitates its absorption in the ileum. Absence or deficiency (pernicious anemia) leads to B₁₂ deficiency, causing megaloblastic anemia and neurological symptoms. HCl activates pepsin, pepsinogen is precursor, mucus protects.