We know that acceleration is related to mass by the expression, a = F/m. Now, if both force and mass are doubled, Acceleration = a₁ = 2F/2m (i.e., acceleration will, remain the same).

Robert Hooke in 1665, while examining a thin slice of cork, discovered dead cells. He used the word cell, which is derived from Latin, that means ‘ a little room’ to describe these units of cork slice.

Companion cells are characteristic element of phloem tissue associated with the sieve tubes in the angiosperms. Thus, they are the part of vascular tissue system. They are absent in pteridophytes and gymnosperms. Guard cells and subsidiary cells are associated with ...

Sclerenchyma tissues are long and narrow as the walls are thickened due to lignin (a chemical substance which acts as cement and hardens them).

Aerenchyma is a special tissue found in hydrophytes (e.g. Hydrilla, Potamogeton, etc.) and some land plants (e.g. petiole of banana, Canna), formed by parenchyma cells. They make a network by leaving wide air spaces (air cavities) for the gaseous exchange ...