UASs (upstream activating sequences) are DNase hypersensitive. This means that ________.
◦ a UAS is constitutively open
◦ each UAS is likely to be single-stranded
◦ more than one strand of DNA exists in each UAS
◦ any given UAS is composed of a double-stranded site with a bound repressor
◦ each UAS has more histone-binding sites than non-UAS sites