AP Ch 17 Biotechnology

Gel electrophoresis is a technique used in genetic engineering to separate fragments of DNA based on their length and electrical charges. It involves placing DNA samples onto a gel and applying an electric current. The negatively charged DNA fragments move towards the positive electrode, with smaller fragments moving faster and traveling further through the gel. This separation allows scientists to analyze and study the different fragments of DNA. The other options listed, such as cutting DNA into fragments, carrying DNA into a new cell, linking fragments together, or making copies of specific segments, do not accurately describe the function of gel electrophoresis in genetic engineering.

DNA ligase is an enzyme that plays a crucial role in recombinant technology by linking together newly joined fragments of DNA. It catalyzes the formation of phosphodiester bonds between adjacent nucleotides, sealing any gaps or nicks in the DNA backbone. This process is essential for the successful construction of recombinant DNA molecules, such as plasmids or vectors, where different DNA fragments need to be joined together. DNA ligase ensures the integrity and stability of the recombinant DNA molecule by sealing any breaks in the DNA backbone, allowing for the proper functioning of the inserted genes or DNA sequences.

The function of the polymerase chain reaction (PCR) in genetic engineering is to make millions of copies of a specific segment of DNA. PCR is a technique that allows scientists to amplify a small amount of DNA into a large quantity. This is done by using specific primers that bind to the DNA segment of interest, and then using a heat-stable DNA polymerase to synthesize new DNA strands. Through a series of temperature cycles, PCR can exponentially replicate the target DNA segment, making it easier to study, manipulate, and analyze.

A vector in genetic engineering is a DNA molecule that is used to carry foreign DNA into a host cell. It acts as a vehicle to transport the desired DNA segment into a new cell where it can be expressed or replicated. This allows genetic engineers to introduce specific genes or genetic material into cells for various purposes such as gene therapy, production of recombinant proteins, or studying gene function.

Polymerase chain reactions (PCR) are a powerful tool in molecular biology that allows for the amplification of specific DNA sequences. By targeting a selected gene sequence, PCR can detect the presence of an infection even before the body has produced antibodies. This is because PCR directly amplifies the genetic material of the pathogen, providing an early and sensitive method for diagnosis. Therefore, the given statement is true.

The correct answer is "all of the above." This means that genetically engineered microorganisms are used to produce all of the mentioned human products, including human growth hormone, insulin, tissue plasminogen activator, and clotting factor VIII. These microorganisms are modified to produce these specific proteins, which can then be harvested and used for medical purposes.

A restriction fragment length polymorphism (RFLP) refers to a variation in the length of DNA fragments that is caused by inherited differences in highly repetitive DNA. These differences can be detected by using restriction enzymes to cut the DNA into fragments and then analyzing the resulting fragment sizes. By comparing the fragment sizes between individuals, it is possible to identify genetic variations and determine if they are associated with certain traits or diseases.