| 1. | Densely packed and transcriptionally inactive |
| 2. | Lightly packed and rich in ribosomes |
| 3. | Site of active gene transcription |
| 4. | Composed entirely of RNA |
| 1. | Histones are a set of positively charged, basic proteins. |
| 2. | Histones are rich in the basic amino acid residues lysine and arginine. |
| 3. | Histones are organised to form a unit of eight molecules called histone octamer. |
| 4. | The positively charged DNA is wrapped around the positively charged histone octamer to form a structure called centrosome. |
An octamer of 4 histones complexed with DNA forms
(1) Endosome
(2) Nucleosome
(3) Mesosome
(4) Centromere
| 1. | Euchromatin is transcriptionally active and loosely packed, while heterochromatin is tightly packed and transcriptionally inactive. |
| 2. | Euchromatin is found only in prokaryotes, whereas heterochromatin is present in eukaryotes. |
| 3. | Heterochromatin undergoes frequent transcription, while euchromatin remains permanently silent. |
| 4. | Heterochromatin contains all coding genes, while euchromatin consists of repetitive DNA sequences. |
| 1. | nucleolus in a nucleus |
| 2. | heterochromatic inactivated X chromosome in females |
| 3. | nucleosome in chromatin |
| 4. | tetrad of paired homologs in first meiosis |

Choose correct one :-
1. a-DNA, b-H-histone, c-histone octamer, d-core of histone
2. a-core of histone, b-DNA, c-H histone, d-histone octamer
3. a-Histone octamer, b-core of histone, c-DNA, d-H histone
4. a-H histone, b-histone octamer, c-core of histone, d-DNA
| Statement I: | The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called a nucleosome. |
| Statement II: | A typical nucleosome contains 200 bp of DNA helix. |
| 1. | Statement I is incorrect; Statement II is correct |
| 2. | Statement I is correct; Statement II is correct |
| 3. | Statement I is correct; Statement II is incorrect |
| 4. | Statement I is incorrect; Statement II is incorrect |
Histones are rich in:
1. Basic amino acids lysine and arginine
2. Acidic amino acids lysine and arginine
3. Basic amino acids glutamate and aspartate
4. Acidic amino acids glutamate and aspartate
A typical nucleosome contains:
1. 40 bp of DNA helix
2. 60 bp of DNA helix
3. 140 bp of DNA helix
4. 200 bp of DNA helix
The length of 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 elimination of repetitive DNA