Biology homework help. A DNA molecule is made of four types of nucleotides Adenine, Guanine, Thymine, and Cytosine. Describe how these nucleotides are connected together to make a DNA strand. How are the two DNA strands in a double-stranded (duplex) DNA molecule arranged relative to one another? How does this double-stranded arrangement make DNA replication possible?Address all Discussion topics in the Discussion area. Your initial post should be at least 100 words and contain references; excluding references. In addition, respond to at least two of your colleagues posts with meaningful comments in accordance with the syllabus. Each post should be at least 50 words. Please be sure to cite all of your sources. NOTES: 1 website and 1 textbook references please.