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.
After binding to the DNA, the RNA polymerase switches from a closed complex to an open complex. This change involves the separation of the DNA strands to form an unwound section of DNA of approximately 13 bp, referred to as the transcription bubble.