How is a large amount of DNA packaged inside a cell?

How is a large amount of DNA packaged inside a cell?

• A. It is folded around proteins and compacted into histones, nucleosomes, and chromosomes.
• B. It remains uncondensed as a long molecule within the nucleus.
• C. It is stored in lipid droplets outside the nucleus.
• D. It is degraded during cell division.

Answer: (A)

DNA packaging relies on wrapping DNA around protein cores to form chromatin, which allows extremely long molecules to fit inside the nucleus. The fundamental unit is the nucleosome, where about 146 base pairs of DNA wrap around a histone protein octamer. These nucleosomes resemble beads on a string; the linking DNA connects them to form chromatin that can be further compacted into higher-order fibers. As this chromatin condenses, it becomes tightly packed into chromosomes during cell division. This organization not only fits the genome into the nucleus but also helps regulate access for processes like transcription and replication. The other ideas don’t fit because DNA is not stored in lipid droplets outside the nucleus, and it is not degraded during division; rather, it is replicated and segregated in its packaged, chromatin form.

DNA packaging relies on wrapping DNA around protein cores to form chromatin, which allows extremely long molecules to fit inside the nucleus. The fundamental unit is the nucleosome, where about 146 base pairs of DNA wrap around a histone protein octamer. These nucleosomes resemble beads on a string; the linking DNA connects them to form chromatin that can be further compacted into higher-order fibers. As this chromatin condenses, it becomes tightly packed into chromosomes during cell division. This organization not only fits the genome into the nucleus but also helps regulate access for processes like transcription and replication.

The other ideas don’t fit because DNA is not stored in lipid droplets outside the nucleus, and it is not degraded during division; rather, it is replicated and segregated in its packaged, chromatin form.