❗Topoisomerase is similar to a COMB, it removes supercoils ahead of the replication fork in order to make sure it isn’t “tangled”. It alleviates TORSIONAL STRESS caused by the DNA being unwinded, as torsional stress causes supercoils. Topoisomerase strategically cuts and rejoins DNA strands and effectively prevents the DNA from becoming tangled, ensuring the replication process proceeds smoothly.

❗ STRs are extremely useful in applications such as the construction of genetic maps (49), gene location, genetic linkage analysis, identification of individuals, paternity testing, as well as disease diagnosis - THE PART OF THE DNA BEING USED FOR THE PCR

D 1.1.1

• DNA replication is the process of producing exact DNA copies with identical base sequences: Produces two exact copies of one DNA molecule
• The purposes of DNA replication are to: Facilitate inheritance and transfer genetic material from one generation to the other, growth repair and regeneration of tissue
• DNA replication results in two DNA molecules, each with one new strand and one original strand

D 1.1.2

• DNA replication is known as semi-conservative, this is because during the replication process, each copy CONSERVES (replicates) the information from one half of the original DNA, conserving that genetic information.
• It’s also known as semi-conservative because when the original DNA strands are split, each half is used as a template to make the new complementary strand
• Complementary Base Pairing ensures that the new DNA double helix is a faithful copy of the original DNA molecule
• Complementary Base pairing also allows nucleic acids to act as templates to create the new Complementary strand, which will consist of complementary nucleotides for the original strand
• The new strands formed are complementary to their template strands but also identical to the other strand that was created when the DNA is split in half. Therefore, complementary base pairing has a big role in the conservation of the base sequence of DNA.

D 1.1.3

• DNA strands must be separate prior to replication because each split strand will serve as a template for it’s newly synthesised complementary strand
• The separation of DNA strands prior to replication also minimises the risks of mismatches or mutations in the DNA. Although there’s a very slim chance of this occurring, separating the DNA strands reduces the possibility of this happening further.
• DNA Helicase is the enzyme that separates/unwinds/unzips the DNA double helix into single strands in order to prepare them for the complementary base pairing process, essentially just making the DNA “Available” for replication
• DNA Polymerase is like DNA helicase’s opposite: It’s the central enzyme used for SYNTHESISING DNA.
• DNA polymerase synthesises the complementary bases and adds nucleotides to conduct base pairing
• There are separate DNA polymerases that work at the same time on both separated strands of the DNA molecule