Question

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

• A. ${10}^3$
• B. ${10}^6$
• C. ${10}^9$
• D. ${10}^{12}$

Answer 1

Answer: (C)

${10}^9$

In DNA molecules there are 2 strands of parents, the DNA number at the end of each cycle is increased in powers of 2.

Calculation:-

DNA multiplies in exponents of 2 for 20 cycles each DNA yields $2^{20}$ copies.

For 1000 DNA $1000\ast \left(2^{20}\right)$=${10}^9$.

So, the correct option is '${10}^9$'.