7. Which of the following is true about YAC vectors?

it is highly stable

it is used in physical mapping

All of these choices are correct

it is a great choice to clone DNA fragments more than 100 kb

All these choices are correct

Explanation:

YACs stands for Yeast artificial chromosomes. These chromosomes are derived from a fungus species Saccharomyces cerevisiae. YACs are genetically modified and a 100-1000 kb fragments of DNA are inserted into a bacterial plasmid. The inserted DNA fragment can be cloned and physically mapped. In the presence of this fragment, the chromosome will be stable during extracellular replication and easily can be differentiated from colonies without the vector.