Which type of protein does DNA wrap around so that it can be packaged in a cell? 1) spliceosome proteins 2)histones 3)ribosomal proteins 4)DNA polymerase 5)topoisomerase Solution Each chromosome consists of one continuous thread-like molecule of DNA coiled tightly around proteins, and contains a portion of the 6,400,000,000 basepairs (DNA building blocks) that make up your DNA. The double helix of DNA is highly negatively charged due to all the negatively charged phosphates in the backbone. All that negative charge must be counterbalanced by a positive charge, and the cell makes proteins called histones that bind DNA and aid in DNA\'s packaging. Histones are positively charged proteins that wrap up DNA through interactions between their positive charges and the negative charges of DNA. Double-stranded DNA loops around 8 histones twice, forming the nucleosome, which is the building block of chromatin packaging. Nucleosomes stack up against one another in organized arrays with multiple levels of packing. The first level of packing is thought to produce a fiber about 30 nanometers (nm) wide. These 30 nm fibers then form a series of loops, which fold back on themselves for additional compacting. The multiple levels of packing that exist within eukaryotic chromosomes not only permit a large amount of DNA to occupy a very small space, but they also serve several functional roles..

1. Which type of protein does DNA wrap around so that it can be packaged in a cell?
1) spliceosome proteins
2)histones
3)ribosomal proteins
4)DNA polymerase
5)topoisomerase
Solution
Each chromosome consists of one continuous thread-like molecule of DNA coiled tightly around
proteins, and contains a portion of the 6,400,000,000 basepairs (DNA building blocks) that make
up your DNA.
The double helix of DNA is highly negatively charged due to all the negatively charged
phosphates in the backbone. All that negative charge must be counterbalanced by a positive
charge, and the cell makes proteins called histones that bind DNA and aid in DNA's packaging.
Histones are positively charged proteins that wrap up DNA through interactions between their
positive charges and the negative charges of DNA. Double-stranded DNA loops around 8
histones twice, forming the nucleosome, which is the building block of chromatin packaging.
Nucleosomes stack up against one another in organized arrays with multiple levels of packing.
The first level of packing is thought to produce a fiber about 30 nanometers (nm) wide. These 30
nm fibers then form a series of loops, which fold back on themselves for additional compacting.
The multiple levels of packing that exist within eukaryotic chromosomes not only permit a large
amount of DNA to occupy a very small space, but they also serve several functional roles.