Freebase(0.00 / 0 votes)Rate this definition: Bollard. A bollard is a short vertical post. Originally it meant a post used on a ship or a quay, principally for mooring. The word now also describes a variety of structures to control or direct road traffic, such as posts arranged in a line to obstruct the passage of motor vehicles.
Which of the following events occurs directly after a DNA molecule is unzipped? A. Mismatched nucleotide bases are identified and replaced. B. Free-floating nucleotides pair up with exposed bases.hich of the following events occurs directly after a DNA molecule is unzipped? A. Mismatched nucleotide bases are identified and replaced. B. Free-floating nucleotides pair up with exposed bases.
DNA helicase unzip, or separate, a strand of DNA at positions  called origins. This means that the hydrogen bonds between  complementary base pairs are removed (DNA is dou â¦ ble stranded!).  When they separate double-stranded DNA into single strands, it  allows each strand to be copied (replication).    DNA helicases use the energy stored in a molecule called ATP to  break the bonds, which serves as the energy currency of cells. 15 people found this useful.