Answer
(a)
The contour length is $$17 \mathrm{\ mm} .$$
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(b)
The length of the DNA is therefore
$$2 \mathrm{\ mm}$$
Work Step by Step
(a)
The contour length is $5 \times 10^{7}$ bp $\times 3.4 \hat{\mathrm{A}} / \mathrm{bp}=1.7 \times 10^{8} \mathrm{A}=17 \mathrm{\ mm} .$
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(b)
The length of the DNA is therefore
$(80 \stackrel{\circ}{\mathrm{A}} / 200 \text { bp }) \times\left(5 \times 10^{7} \text { bp }\right)=2 \times 10^{7} \stackrel{\circ}{\mathrm{A}}=2 \mathrm{\ mm}$
