Answer:
DNA is tightly packed up to fit in the nucleus of every cell. As shown in the animation, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin, in turn, loops and folds with the help of additional proteins to form chromosomes. Condensing DNA into chromosomes prevents DNA tangling and damage during cell division.
Explanation:
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BioSafety Level (BSL) 3 labs,
perform work with indigenous or exotic agents that may cause serious or
potentially lethal diseases through the inhalation exposure. Biological Safety
Levels (BSL) are a sets of protections assigned to the activities that occur in
specific biological laboratories. BSL protects laboratory workers, the
surrounding environment and also the community.