Many weed killers work because they destroy the outside of plant cells, killing the entire plant. Which structure do these chemicals target

because the light is a great source of energy for the plants to survive. (i hope this )

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.