The diagram shows a mutation in the human beta-globin gene. The effect of the mutation is sickle-shaped red blood cells, which is the cause of sickle cell disease. Sickle cell disease provides an example for which principle of molecular genetics?

the answer would be d

blah

explanation:

bc blah

i'll try what topic lol

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.