Which organelle is called the 'kitchen of the cell'? MCQ with Answer and Explanation

Explanation:
Sclerenchyma is a simple permanent tissue composed of dead cells with extremely thick, lignified, and pitted cell walls. These cells (fibers and sclereids) are narrow, elongated, and provide rigid mechanical strength, allowing plant parts to withstand bending and pressure. Collenchyma provides flexible support in growing parts, and parenchyma is for storage and photosynthesis (chlorenchyma).

Explanation:
The stapes (stirrup) in the middle ear is the smallest bone, measuring about 3 mm. It transmits sound vibrations to the inner ear.

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.