NEET BIOLOGY

Detailed explanation-1: -Seedling emergence occurs as a result of the elongation of the mesocotyl (negative gravitropism) that elevates the coleoptile or “spike” toward the soil surface (Rodríguez & Cassab, 2021).

Detailed explanation-2: -As seeds imbibe water, they expand and enzymes and food supplies become hydrated. Hydrated enzymes become active and the seed increase its metabolic activities to produce energy for the growth process. In addition, the water causes turgor pressure to increase in the cells and they are able to enlarge.

Detailed explanation-3: -Two environmental signals impact seedling emergence directly: light and mechanical disturbance. As a seedling penetrates upward through soil, it encounters decreased mechanical resistance, but increased light.