Why can scratching or chipping the seed coat speed up the germination of hard-coated seeds like alfalfa?

Question

Quizplus · Accepted Answer

Scratching or chipping the seed coat allows water and oxygen to enter the seed more easily, which can speed up germination. This is because water is necessary for the seed to begin metabolic processes that lead to germination, and oxygen is needed for respiration to occur, which provides energy for growth. By allowing water and oxygen to reach the embryo more quickly, the seed can begin germinating sooner.

Why Can Scratching or Chipping the Seed Coat Speed Up