The participants in a daisy chain can be of any and all genders.
A variation on the daisy chain involves just three people. The person in the center of this group is penetrated, either vaginally or anally, by one partner while they perform oral sex on the other participant. This sexual practice is known colloquially as the spit roast.
Another variant sees the participants in the chain manually stimulating one another, instead of performing oral sex. Homosexual or bisexual men may also practice a version where each participant engages in anal sex with the next person in the chain.