Why does the body attack a transplanted organ?

A transplanted organ is viewed by our bodies immune system as a foreign object, much like when we get sick. Our body is just trying to protect itself. For this reason people that have a transplant have to take immunosuppression medication for the rest of their lives.

the backbone of the dna and rna compound is sugar phosphate.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.