Final answer:
Two modifications that protect viral DNA from being recognized by endonucleases are methylation of specific sequences and packing the DNA structure.
Step-by-step explanation:
Two modifications that protect viral DNA from being recognized by endonucleases are methylation of specific sequences and packing the DNA structure.
There are two modifications that protect viral DNA from being recognized by endonucleases:
- Methylation of specific sequences: Viral DNA can be modified by adding methyl groups to specific sequences. These modifications prevent endonucleases from recognizing and cutting the viral DNA, thus protecting it. The methylated sequences act as a signal to the cell's own restriction endonucleases to distinguish between self and non-self DNA.
- Packed DNA structure: Viral DNA can be tightly packed or wrapped with proteins, making it less accessible to endonucleases. This physical protection prevents the endonucleases from reaching and cleaving the viral DNA.