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BIOXII06: MOLECULAR BASIS OF INHERITANCE

342905 Read (i) to (v) and find the correct option
i. Nitrogen base is linked to pentose sugar through $N$ -glycosidic linkage
ii. Phosphate group is linked to $OH$ of a nucleoside through phosphoester linkage
iii. Two nucleosides are linked through $N$ -glycosidic linkage
iv. Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome
v. Chromatin that is more densely packed and stains dark is called euchromatin

1 i alone is wrong

2 iv alone is wrong

3 iii and v are wrong

4 i, ii, iii wrong

Explanation:

iii and v are wrong.
• i is correct as nitrogen bases are indeed linked to the pentose sugar through $N$ -glycosidic linkage.
• ii is correct as the phosphate group is linked to the $OH$ of a nucleoside through phosphoester linkage.
• iii is incorrect because nucleosides are not linked through $N$ -glycosidic linkage; instead, they are linked by phosphodiester bonds to form the sugar-phosphate backbone of DNA or RNA.
• iv is correct as DNA is wrapped around a positively charged histone octamer to form a nucleosome.
• v is incorrect because euchromatin is less densely packed and stains lightly, while heterochromatin stains dark.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342906 Refer to the given figure of nucleosome, and select the correct option:
supporting img

1 Structure A is

H_{1}

protein, which is rich arginine and aspartic acid.

2 Structure A is the histone core with two molecules each of four histone proteins.

3 Structure C is single-stranded DNA made up of 200 nucelotides.

4 Structure B is called Nu-Body, which has five types of histone proteins.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342907 Statement A :
Histones are basic proteins of major importance in packaging of eukaryotic DNA, DNA and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Statement B :
Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3 A}$ and $H_{4 A}$ .

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

In eukaryotes, nucleosomes are basic unit of DNA packaging, consists of DNA segment wrapped around eight histone protein cores in a sequence. DNA forms a nucleosome along with histone octamer which consists a big portion of chromatin. Generally, Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3}$ and $H_{4}$ .

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342905 Read (i) to (v) and find the correct option
i. Nitrogen base is linked to pentose sugar through $N$ -glycosidic linkage
ii. Phosphate group is linked to $OH$ of a nucleoside through phosphoester linkage
iii. Two nucleosides are linked through $N$ -glycosidic linkage
iv. Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome
v. Chromatin that is more densely packed and stains dark is called euchromatin

1 i alone is wrong

2 iv alone is wrong

3 iii and v are wrong

4 i, ii, iii wrong

Explanation:

iii and v are wrong.
• i is correct as nitrogen bases are indeed linked to the pentose sugar through $N$ -glycosidic linkage.
• ii is correct as the phosphate group is linked to the $OH$ of a nucleoside through phosphoester linkage.
• iii is incorrect because nucleosides are not linked through $N$ -glycosidic linkage; instead, they are linked by phosphodiester bonds to form the sugar-phosphate backbone of DNA or RNA.
• iv is correct as DNA is wrapped around a positively charged histone octamer to form a nucleosome.
• v is incorrect because euchromatin is less densely packed and stains lightly, while heterochromatin stains dark.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342906 Refer to the given figure of nucleosome, and select the correct option:
supporting img

1 Structure A is

H_{1}

protein, which is rich arginine and aspartic acid.

2 Structure A is the histone core with two molecules each of four histone proteins.

3 Structure C is single-stranded DNA made up of 200 nucelotides.

4 Structure B is called Nu-Body, which has five types of histone proteins.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342907 Statement A :
Histones are basic proteins of major importance in packaging of eukaryotic DNA, DNA and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Statement B :
Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3 A}$ and $H_{4 A}$ .

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

In eukaryotes, nucleosomes are basic unit of DNA packaging, consists of DNA segment wrapped around eight histone protein cores in a sequence. DNA forms a nucleosome along with histone octamer which consists a big portion of chromatin. Generally, Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3}$ and $H_{4}$ .

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342905 Read (i) to (v) and find the correct option
i. Nitrogen base is linked to pentose sugar through $N$ -glycosidic linkage
ii. Phosphate group is linked to $OH$ of a nucleoside through phosphoester linkage
iii. Two nucleosides are linked through $N$ -glycosidic linkage
iv. Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome
v. Chromatin that is more densely packed and stains dark is called euchromatin

1 i alone is wrong

2 iv alone is wrong

3 iii and v are wrong

4 i, ii, iii wrong

Explanation:

iii and v are wrong.
• i is correct as nitrogen bases are indeed linked to the pentose sugar through $N$ -glycosidic linkage.
• ii is correct as the phosphate group is linked to the $OH$ of a nucleoside through phosphoester linkage.
• iii is incorrect because nucleosides are not linked through $N$ -glycosidic linkage; instead, they are linked by phosphodiester bonds to form the sugar-phosphate backbone of DNA or RNA.
• iv is correct as DNA is wrapped around a positively charged histone octamer to form a nucleosome.
• v is incorrect because euchromatin is less densely packed and stains lightly, while heterochromatin stains dark.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342906 Refer to the given figure of nucleosome, and select the correct option:
supporting img

1 Structure A is

H_{1}

protein, which is rich arginine and aspartic acid.

2 Structure A is the histone core with two molecules each of four histone proteins.

3 Structure C is single-stranded DNA made up of 200 nucelotides.

4 Structure B is called Nu-Body, which has five types of histone proteins.

BIOXII06: MOLECULAR BASIS OF INHERITANCE

342907 Statement A :
Histones are basic proteins of major importance in packaging of eukaryotic DNA, DNA and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Statement B :
Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3 A}$ and $H_{4 A}$ .

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

In eukaryotes, nucleosomes are basic unit of DNA packaging, consists of DNA segment wrapped around eight histone protein cores in a sequence. DNA forms a nucleosome along with histone octamer which consists a big portion of chromatin. Generally, Histones are five major types $H_{1}, H_{2} A, H_{2} B, H_{3}$ and $H_{4}$ .