Astudent wants to determine his maternal lineage. he swabs his cheeks to isolate mitochondrial dna, adds it to a solution of chelex and uses pcr to amplify a target sequence. why was chelex used? select one: a. since dnaases use magnesium as a cofactor, chelex binds to all the magnesium ions in the cheek cell extract to prevent dna degradation. b. chelex inhibits dnaases directly to prevent dna degradation in the cheek cell swab. c. chelex is an enzyme that greatly increases the rate of the pcr reaction. d. using chelex increases the chances that pcr will occur. e. chelex will prevent the dna from melting at high temperatures.