Final answer:
To clone a very large piece of DNA (over 100,000 base pairs), a Bacterial Artificial Chromosome (BAC) should be used as a bacterial cloning vector.
Step-by-step explanation:
To clone a very large piece of DNA (over 100,000 base pairs), Bacterial Artificial Chromosome (BAC) should be used as a bacterial cloning vector. BACs can accommodate larger DNA inserts and can hold fragments that are much larger than plasmids or bacteriophages. They are commonly used for cloning large genomes and allow for the study of specific genes or noncoding regions.