Question

please andwer all the questions

7) Describe at least two major intramolecular forces that help stabilize the DNA double-helix? 8) In mammalian female cells, the DNA of the Barr Body is characteristic of: a) Heterochromatin b) Euchromatin c) Dispersed chromatin d) Patemal DNA ONLY e) Maternal DNA ONLY 9) When used to describe the RNA polymerases' activity, the term “processivity” refers to: a) The ability to recognize and bind to a promoter region b) The ability to remain attached to DNA c) The ability to add nucleotide triphosphates to a growing RNA chain d) The ability to correct errors in base mismatching e) The ability to detach quickly from DNA 10) Describe the structure of a nucleosome (be sure to include as much information as possible for full credit) 01) The enzyme that catalyzes the addition of additional bases on the ends of chromosomes is referred to as: a) a centromere b) sister chromatid c) telomerase d) telomere e) kinase B Focu

Answer 1

Question 7 -

ANSWER-

major intra molecular force that stablize DNA double helix structure-

• Phosphodiester bond
• Hydrogen bond

DNA double helix structure -

• watson and crick proposed a double helix structure of DNA .
• One main hallmark of double helix medel is complementary base pairing between purines pyrimidine.
• DNA is composed of two polynucleotides chain.
• Both the polynucleotides chain are complementary and antiparallel to each other.

phosphodiester Bond-

• It is a covalent bond.
• It is the linkage between the 3' carbon atom of one sugar molecule and 5' carbon atom of another sugar molecule.
• It make up the backbone of strand of DNA .
• In both strand of DNA direction of phosphodiester bond is opposite. i. e. if direction of phosphodiester bond in one strand is 3'-5' then it is 5'-3' in another strand.

Hydrogen Bond-

• Both strand of DNA held together by hydrogen bonds.
• These hydrogen bonds are present between nitrogenous base of both strand.
• In a DNA molecule one purine always pairs with a pyrimidine.
• Adenine binds to thymine by two hydrogen bond and cytosine binds to guanine by three hydrogen bonds.

Question 17- which is DNA strand ,serves as a template for transcription?

ANSWER- (c) antisense strand

Antisense strand -

• out of two strand of DNA only one strand participate inin transcription, this strand is called as Antisense strand.
• It is also called as non coding strand or template strand.
• It is in 5' -3' direction.
• It is transcribed into mRNA.