A linear shaped piece of DNA strand is obtained when a plasmid is cut HindIII, Apa1, and Sma1.
Explanation:
Restriction enzymes are endonucleases which enzymatic proteins which can cut a DNA at specific sequences at particular recognition sites. The sequences recognized by these enzymes are usually palindromic that occurs for a definite length (6 bp, 4 bp, or 8 bp).
They can either be blunt cutters or sticky end cutters. APA1, SMA1, and HindIII are all restriction enzymes which can cut a circular plasmid at specific locations.
These restriction enzymes bind with the DNA at specific locations and cuts them to give linear strands of DNA either with a blunt or a sticky end.