Which of the following diseases is caused by a protozoan transmitted by the tsetse fly? MCQ with Answer and Explanation

Explanation:
The stomach secretes gastric juice containing hydrochloric acid and the enzyme pepsin, which initiates the digestion of proteins into smaller peptides. The small intestine is the primary site for the final digestion of food and the absorption of most nutrients (amino acids, simple sugars, fatty acids, vitamins) into the bloodstream through its villi. The large intestine (colon) primarily absorbs water, electrolytes, and some vitamins produced by gut bacteria, forming solid feces. All statements are correct.

Explanation:
Arthropoda is the largest phylum, characterized by jointed appendages, segmented body, and chitinous exoskeleton. Examples: insects, crustaceans, arachnids. Mollusca have a muscular foot and shell, Annelida have segmented worms, Echinodermata have spiny skin and radial symmetry. Arthropods have an open circulatory system.

Explanation:
Bacteria exhibit diverse nutritional modes; some are autotrophic (photosynthetic like cyanobacteria or chemosynthetic), while others are heterotrophic (saprophytic or parasitic). Fungi are eukaryotic organisms, characterized by having a true nucleus and membrane-bound organelles, and are heterotrophic. Viruses are considered non-living outside a host cell because they lack metabolic machinery and cannot replicate independently; they only exhibit living characteristics inside a host. Thus, statements 1 and 3 are correct.