The two strands of a dna double helix are held together by:
a. ionic bonds.
b. hydrogen bonds.
c. nonpolar covalent bonds.
d. polar covalent bonds.
e. hydrophobic exclusions.

equal distribution i think.

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.