Researchers clone a fragment of DNA by inserting it into a ____.

A) vector
B) CRISPR
C) restriction enzyme
D) chromosome
E) sister chromatid

DNA fragments can be cloned by inserting them into a vector, which is a small piece of DNA, such as a plasmid, that can replicate independently of the host cell's chromosome. The cloned fragment can then be amplified and manipulated for various applications, such as gene expression studies or genetic engineering. CRISPR is a genetic tool used for genome editing, while restriction enzymes are used for cutting DNA at specific sites. Chromosomes and sister chromatids are parts of the cell's genetic material, but they are not directly involved in cloning DNA fragments.