Genetic Enegineering Forensics And Biology

Explanation
Restrictive enzymes, also known as restriction enzymes, are enzymes that cleave DNA into fragments by recognizing specific DNA sequences and cutting the DNA at or near those sequences. These enzymes are commonly used in molecular biology techniques, such as DNA cloning and genetic engineering, to manipulate and analyze DNA. Ligase is an enzyme that joins DNA fragments together, DNA synthase is not a recognized enzyme, and lactase is an enzyme that breaks down lactose, not DNA.

Explanation
In Gel Electrophoresis, an electrical current is applied to the gel, causing the negatively charged DNA fragments to move towards the positive end. The smaller DNA fragments will move faster and farther compared to the larger fragments due to their size and charge. Therefore, the correct answer is "farthest."

Explanation
PCR (Polymerase Chain Reaction) is a technique used to amplify or make multiple copies of specific fragments of DNA. It involves a series of temperature cycles that allow the DNA to be denatured, or separated into single strands, and then replicated using a DNA polymerase enzyme. By repeatedly cycling through these temperature changes, PCR can produce millions or even billions of copies of a specific DNA sequence from a small starting amount. This is useful in various applications such as genetic research, forensic analysis, and medical diagnostics, where a large amount of DNA is needed for analysis.

Explanation
Fingernails do NOT contain DNA. IF you scratch someone with your nails, DNA can be found, sometimes, under the nails. The shafts of hair do NOT normally contain DNA. IF the hair is ripped from the head (contains the hair follicles and skin tags), then it will contain DNA.

Explanation
There are approximately 3 billion base pairs in the human genome (Human genome: ALL the nitrogenous bases on the 46 chromosomes found in a cell).