Final answer:
In strand displacement amplification, instead of heat denaturation, enzymes that are not affected by high temperatures are used. Taq polymerase, derived from Thermus aquaticus, is one such enzyme that remains stable through multiple heating and cooling cycles.
Step-by-step explanation:
In strand displacement amplification, an alternative to heat denaturation is the use of enzymes that are not affected by the high temperatures needed to separate the DNA strands. One such enzyme that can be used is Taq polymerase, which is derived from the thermophilic bacteria Thermus aquaticus. Taq polymerase remains stable through multiple heating and cooling cycles, allowing for the amplification of DNA without the need to add additional enzyme after each heating.