A 7.5kb linear DNA fragment was cleaved with HindIII, Smal, and a combination of the two enzymes. HindIII cleaved the fragment into 2.5kb and 5kb pieces, Smal into 2kb and 5.5kb pieces, and the combined enzymes into 2.5kb, 3kb, and 2kb pieces. When the combined enzyme fragments were further digested with EcoRI, the 3kb fragment was lost and a 1.5kb fragment appeared, indicating an EcoRI cleavage site within the original 3kb fragment.

1. A linear fragment of DNA (7.5kb) is cleaved with the individual restriction enzymes HindIII
and SSmal and then with a combination of the two enzymes. The fragments obtained are:
HindIII: 2.5kb,5kb Smal: 2.0kb,5.5kb HindIII and Smal: 2.5kb,3.0kb,2.0kb a) Draw the
restriction map. (6 points) b) The mixture of fragments produced by the combined enzymes is
cleaved with the enzyme EcoRI, resulting in the loss of the 3-kb fragment (band stained with
ethidiuium bromide on an agarose gel) and the appearance of a band stained with ethidium
bromide representing a 1.5-kb fragment. Mark the EcoRI cleavage site on the restriction map. (2
points) c) Draw the gel that these data would yield using a 1000bp ladder as a standard if loaded
as follows: (6 points) Lane 1 - 1000 bp standard, Lane 2 - HindIII, Lane 3 - Smal, Lane 4 -
HindIII, Smal, EcoRI