The gland responsible for regulating circadian rhythms 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:
Insulin stimulates GLUT4 transporters to move to the cell membrane, increasing glucose uptake in muscle and adipose tissue. Glucagon raises blood glucose.

Explanation:
The right lung has three lobes, the left has two (to accommodate the heart). So C is incorrect.