The causative agent of Kala-azar (visceral leishmaniasis) is: MCQ with Answer and Explanation

Explanation:
Streptococcus thermophilus and Lactobacillus bulgaricus are used as starter cultures in yogurt production. They ferment lactose to lactic acid, causing milk proteins to coagulate, giving yogurt its thick texture and tangy taste. Bacillus cereus causes food poisoning, E. coli can be pathogenic, Salmonella causes typhoid.

Explanation:
Intervertebral discs are fibrocartilaginous joints (symphyses) that allow slight movement and absorb shock. Hinge joints are in knee/elbow, ball-and-socket in hip/shoulder, sutures are immovable fibrous joints in skull.

Explanation:
A food chain shows the flow of energy from producer to consumers. Grass (producer) → Grasshopper (primary consumer/herbivore) → Frog (secondary consumer/carnivore) → Snake (tertiary consumer). Arrows point in the direction of energy flow. Option A has incorrect order, C and D start with consumer. Typically, energy decreases at each trophic level. This illustrates the correct trophic sequence.