Answer:
Option d , speed over time - like running
Explanation:
Force is mathematical terms in defined as a product of mass of an object and it acceleration.
Acceleration is caused when speed changes over time.
Among all the given options, in option D the speed over time will cause acceleration and thus produce a force.
Force being a vector quantity required change of speed in some direction. While running , both quantity and direction can be assumed to be changing.
Thus, option D is correct.
Answer:
Gaseous exchange
Explanation:
In terrestrial plants, gaseous exchange occurs mainly in leaves and to a lesser extent in the roots and stems. In leaves, the structures involved in gaseous exchange are stomata and spongy mesophyll tissues.
The stoma comprises of a stomatal pore and two specialized guard cells. The guard cells are structurally adapted by having chloroplasts, thicker, inelastic inner walls and thinner and elastic outer walls.
The stomata mostly opens during the day. They open when the guard cells are turgid.When the guard cells are flaccid, the thinner outer wall shrinks. The inner thicker walls curvature reduces causing the stomata to close.
Really? A. lol (no trees = unstable environment)
