Final answer:
DNA is a molecule that carries genetic information and can be isolated by breaking open cells. DNA differs between individuals, and molecular biology tools can be used to compare DNA. Restriction enzymes and gel electrophoresis are used to study DNA fragments.
Step-by-step explanation:
DNA, or deoxyribonucleic acid, is a molecule that carries genetic information in all living organisms. It is composed of nucleotides and has a double helix structure. Scientists isolate DNA by breaking open cells and enzymatically destroying other macromolecules. They use methods like gel electrophoresis to separate and visualize DNA fragments. DNA differs from person to person due to variations in the sequence of nucleotides. Tools of molecular biology, such as PCR and DNA sequencing, can be used to compare the DNA of two individuals.
Restriction enzymes are enzymes that cleave DNA at specific recognition sites. They are used in molecular biology to cut DNA into fragments. Restriction fragment length polymorphisms (RFLPs) are variations between individuals in the length of DNA fragments generated by restriction enzymes. Gel electrophoresis is a technique used to separate DNA fragments based on their size and charge. In gel electrophoresis, DNA fragments are loaded onto an agarose gel and subjected to an electric current. The smaller fragments move faster and travel farther, while the larger fragments move slower and stay closer to the top. The results of gel electrophoresis can be interpreted by visualizing the bands produced and determining the sizes of the DNA fragments.