Oxygen and food are delivered to the body's cells by

dna damages cause changes in the structure of the genetic material and prevents the replication mechanism from functioning and performing properly. dna damage and mutation have different biological consequences. while most dna damages can undergo dna repair, such repair is not 100% efficient.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

answer///africa and asia;