题目

The polymerase chain reaction (PCR) requires template DNA,primers,DNA polymerase,and __________.
A DNA ligase
B reverse transcriptase
C plasmid DNA
D a mixture of the four nucleotides A,T,C,G
E a mixture of the four fluorescent nucleotides that terminate elongation of the strand
One concern regarding the use of transgenic plants is the __________.
A inability to produce edible vaccines against infectious diseases
B loss of crop biodiversity,leading to potential widespread crop failures
C documentation of serious adverse health effects from transgenic products in the United States
D difficulty to regenerate entire plants with desired traits from plant cells with the desired DNA
E the ability of current transgenic varieties to pass the genetic trait on to the next generation

提问时间：2020-10-22

答案