The reason why eukaryotic cells are in need of turning on
and off their genes when necessary because of the reason that they may feel
stress because they are under stress as they have the responsibility of acting
immediately when they needed and by that, they need to be turned on or off in means
of adapting to the stress that they experience.
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate.
