List I | List II | ||
A. | Histones | I. | Loosely packed chromatin |
B. | Nucleosome | II. | Densely packed chromatin |
C. | Euchromatin | III. | Positively charged basic proteins |
D. | Heterochromatin | IV. | DNA wrapped around histone octamer |
Statement I: | In prokaryotes, the positively charged DNA is held with some negatively charged proteins in a region called nucleoid. |
Statement II: | In eukaryotes, the negatively charged DNA is wrapped around the positively charged histone octamer to form nucleosome. |
(a) | Euchromatin is loosely packed chromatin. |
(b) | Heterochromatin is transcriptionally active. |
(c) | Histone octomer is wrapped by negatively charged DNA in nucleosome. |
(d) | Histones are rich in lysine and arginine. |
(e) | A typical nucleosome contains 400 bp of DNA helix. |
With respect to nucleosome, which of the following statements is incorrect ?
1. | Nucleosome contains 120 bp of DNA helix. |
2. | Nucleosomes are seen as 'beads' on string' under Electron Microscope. |
3. | DNA is wrapped around positively charged histone octamer to form nucleosome. |
4. | Nucleosome is the repeating unit of chromatin. |
Which one of the following statements about Histones is wrong?
1. | Histones are rich in amino acids - Lysine and Arginine. |
2. | Histones carry a positive charge in the side chain. |
3. | Histones are organized to form a unit of 8 molecules |
4. | Histones are organized to form a unit of 10 molecules |
The association of histone H1 with a nucleosome indicates:
1. DNA replication is occurring
2. The DNA is condensed into a chromatin fibre
3. The DNA double helix is exposed
4. Transcription is occurring
The length of the DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?
1. Deletion of non-essential genes
2. Super-coiling in nucleosomes
3. DNAse digestion
4. Through the elimination of repetitive DNA