1.) For all of the above
2.) supplementary single-stranded ends.
3.) The strong negative charges from the phosphate groups in the DNA backbone cause it to migrate toward the positive pole.
Bones: they lose calcium, becoming crispy
Muscle: they lose mass
Cartilage: becomes stiffer, but it does not make airway more rigid
D) connective tissue: It includes bone, blood, and lymph tissue, giving support to the skin and internal organs, becoming increasingly stiff when aging.
It should be connective tissue.
5. Because of rain and oxygen, if a set of tools is left outdoors in the rain for a long time, it will rust.
6. Yes, I believe it is possible for any of the earth materials scenes to be affected by both mechanical and Chemical weathering, but I am more positive about #5.