Nucleosome

Q.

If the length of E.coli DNA is 1, 360 micron then what is the number of base pairs in this DNA?

1. $4\times {10}^7$
2. $4\times {10}^8$
3. $4\times {10}^6$
4. $4\times {10}^9$

Q. Read the following statements and select the correct option.
(i) Loosely packed and lightly stained region of chromatin is called as heterochromatin.
(ii) Densely packed and dark stained region of chromatin is called as euchromatin.
(iii) A typical nucleosome contains 200 bp of DNA helix.

1. All statements are true
2. Statements (i) and (ii) are true, but statement (iii) is false
3. Statements (ii) and (iii) are true, but statement (i) is false
4. Statements (i) and (ii) are false, but statement (iii) is true

Q. Why does cytosine make pair with guanine and not with Adenine?

1. C—A pair would be wider than double
2. Hydrogen bond forming functional groups are not complementary between C and A
3. Polar nature of C and A
4. C—A pair would not reach across the double helix

Q. In tertiary structure of DNA, what is a histone octamer?

1. A complex consisting of eight positively charged histone proteins (two of each $H_{2}A,H_{2}B,H_3$ and $H_4$) that aid in the packaging of DNA.
2. A complex consisting of eight negatively charged histone proteins (two of each $H_{2}A,H_{2}B,H_3$ and $H_4$) that aid in the packaging of DNA.
3. A complex consisting of nine positively charged histone proteins ($H_1$ and two of each $H_{2}A,H_{2}B,H_3$ and $H_4$) that aid in the packaging DNA.
4. A complex consisting of nine negatively charged histone proteins ($H_1$ and two of each $H_{2}A,H_{2}B,H_3$ and $H_4$) that aid in the packaging of DNA.

Q. Animal cell lacking nuclei would also lack :

1. chromosome
2. ER
3. ribosome
4. lysosome

Q.

What are the structures called that give an appearance as ‘beads on a string’ in the chromosomes when viewed under an electron microscope?

1. Genes
2. Nucleotides
3. Nucleosomes
4. Base pairs

Q. Sequence of nitrogen bases in coding strand of DNA was found to be CAT GTT TAT CGC. What would be sequence of nitrogen bases in mRNA synthesised over the corresponding region of template strand

1. CAA GAA TAU GCC
2. CAU GUU UAU CGC
3. GTA CAA ATA GCC
4. GUA CAA AUA GCC

Q. The given figure shows the structure of nucleosome with their parts labelled as A, B & C. Identify A, B and C.

1. A – DNA; B – H1 histone; C – Histone octamer
2. A – H1 histone; B – DNA; C – Histone octamer
3. A – Histone octamer; B – RNA; C – H1 histone
4. A – RNA; B – H1 histone; C – Histone octamer

Q. 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 nucleosome
3. DNAase digestion
4. Through elimination of repetitive DNA

Q. Chromatosome constitutes

1. nucleosome and RNA
2. nucleosome and NHC proteins
3. RNA and linker DNA
4. nucleosome and linker DNA

Q. If there are 6000 base pairs in DNA, then its length would be?

1. 1040m
2. 1020pm
3. 4020nm
4. 2040nm

Q. The common feature amongst nucleus, chloroplast and mitochondria is

1. Lamellae
2. DNA
3. Cristae
4. All the above.

Q. Explain the role of histones in forming a nucleosome. [2 Marks]

Q. Which of the following is a DNA containing plant virus?

1. Tobacco mosaic virus
2. Tomato mosaic virus
3. Cauliflower mosaic virus
4. Potato mosaic virus

Q.

Give one example of a nitrogen base in DNA.

Q.

What is DNA folding?

Q.

Secondary structure of protein is

1. Alpha - helix

2. B - pleated

3. B - helix

4. Both a and b

Q. If the length of E. coli DNA is 1.36 mm, then what will be the number of base pairs if distance between two consecutive base pairs is 0.34 nm?

1. $6.6\times {10}^9$bp
2. $3.3\times {10}^9$bp
3. $4.0\times {10}^6$bp
4. $2.3\times {10}^6$bp

Q. What is true about telophase stage of mitosis?

1. Nuclear envelope nucleolus, Golgi complex and ER reform
2. Chromosomes lose their identity as discrete elements
3. Chromosomes cluster at opposite spindle poles,
4. All of these

Q. RNA is genetic material in

1. Bacterium
2. Bacteriophage
3. Protozoan
4. TMV

Q. List any two living characteristics of virus.

Q. Double stranded RNA viruses are known as

1. Arboviruses
2. Riboviruses
3. Reoviruses
4. Ribovira

Q. What is the function of non-histone protein?

Q. Non histone proteins are required in eukaryotes only or in prokaryotes also?

Q. Read the following statements and select the Correct option.
(i) Loosely packed and lightly stained region of chromatin are called as heterochrormatin.
(ii) Densely packed and dark stained region of chromatin are called as euchromatin.
(iii) A typical nucleosome contains 200 bp of DNA helix.

1. Statements (i) and (ii) are true, but statement (iii) is false.
2. Statements (i) and (ii) are false, but statement (iii) is true.
3. Statements (ii) and (iii) are true, but statement (i) is false.
4. All the statements are true.

Q. Number of histone proteins in each nucleosome core is

1. $8$
2. $10$
3. $12$
4. $14$

Q. A typical nucleosome contains

1. 400bp of DNA helix
2. 300bp of DNA helix
3. 200bp of DNA helix
4. 100bp of DNA helix

Q. RNA is genetic material __

1. Bacteria
2. cyanobacteria
3. Bacteriophasge
4. Plant viruses

Q. An octamer of four histones complex with DNA is called

1. Endosome
2. Raff
3. Nucleosome
4. Nucleotin

Q. How to insert part of Dna to.other Dna segment