Answer:
<u>A chemical bond between the phosphate group of one nucleotide and the sugar of a neighboring nucleotide holds the backbone together. Chemical bonds (hydrogen bonds) between the bases that are across from one another hold the two strands of the double helix together.</u>
Explanation:
Answer:
Shape of Red Blood Cells Erythrocytes are biconcave discs with very shallow centers. This shape optimizes the ratio of surface area to volume, facilitating gas exchange. It also enables them to fold up as they move through narrow blood vessels.
Answer: because its a chemical
Explanation: i dont know for sure but here is my theroy the animls eat it and it goes through out the ecosystem i dont want to get into to much detail but it can spread bc its a chemical it has a atomic number of 6