The structure that produces ribosomes in the nucleus is the: MCQ with Answer and Explanation

Explanation:
Stomata are microscopic pores typically on the lower epidermis of leaves, bounded by two guard cells that regulate opening and closing for gas exchange (CO₂ in, O₂ out) and transpiration. Lenticels are on bark, hydathodes release water droplets (guttation), sclereids are thick-walled sclerenchyma cells. Stomatal density varies with environmental conditions.

Explanation:
Essential fatty acids are polyunsaturated fats that the human body lacks the enzymes to synthesize, so they must be consumed in the diet. The two primary essential fatty acids are linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). They are precursors for other important lipids like arachidonic acid and are crucial for cell membrane structure and eicosanoid synthesis. Palmitic and stearic are saturated fats.

Explanation:
Phycocyanin is a blue phycobiliprotein pigment present in cyanobacteria (blue-green algae), along with chlorophyll a. Phycoerythrin is red, carotene orange. Phycobilins are accessory pigments that capture light energy for photosynthesis.