At which temperature a DNA molecule is denatured by heat in PCR

DNA is denatured by :

The structure of a protein can be denatured by heat.

Which one of the following statements are incorrect about the properties of DNA? I. DNA is denatured when heated up to 70^(@) II.DNA shows high absorption of UV radiation at 260 m mu III.DNA directly participates in protein synthesis IV. Pyrimidines of DNA are cytosine and thymine

A: Taq Polymerase is involved in PCR technique. R: This enzyme remain active during the high temperature including denaturation of double stranded DNA.

A: Taq Polymerase is involved in PCR technique. R: This enzyme remain active during the high temperature including denaturation of double stranded DNA.

A: Taq Polymerase is involved in PCR technique. R: This enzyme remain active during the high temperature including denaturation of double stranded DNA.

If the initial number of template DNA molecules in a PCR reaction is 1000,the number of product DNA molecules at the end of 20 cycles will be closest to: