Three roles of the DNA molecule in heritage are in storage, copying and transmitting genes.
A-DNA: It is a right-handed double helix similar to the B-DNA form. ...
B-DNA: This is the most common DNA conformation and is a right-handed helix. ...
Z-DNA: Z-DNA is a left-handed DNA where the double helix winds to the left in a zig-zag pattern.
Maybe this helps ? Please look at the picture
DNA is a negatively-charged molecule. Also cell membranes are negatively charged. The problem would be how to push this charges together? I<span>f you put some CaCl2 into the mixture, the CaCl2 will "split" giving 2Cl- and Ca2+. This last ion will be attracted by the negatively charged DNA and will "cover" it, hiding its negative charge. Hope this answers the question.</span>
It's 4. just took it, that's 1000% the right answer. that other person stinks for that non-answer, sorry. hope this helps.
ps. if it's not obvious, you figure it out by taking the hypotenuse (120) and putting it over the height (30). 120/30 is pretty simple division.