Question

Which of the following statements is true for DNA only? ( it can be more than one)

A. It contains the pyrimidine thymine.

B. Bases are attached to sugars in an α-N-glycosidic linkage.

C. It contains the sugar ribose.

D. It contains a 2' hydroxy group.

Which of the following statements is true for both DNA and RNA? ( can only be one)

A. Both can be hydrolyzed in alkaline solution.

B. In base composition, %G = %C.

C. In base composition, %T = %G always.

D. Sugars are connected with a 3'-5' phosphodiester link.

Classify the descriptions as pertaining only to nucleosides.( can be more than one)

A. do not contain a phosphate group

B.may contain either ribose or deoxyribose.

C. contain a base, a monosaccharide, and a phosphate group.

D. are found in RNA and DNA

E. the product when a base binds to carbon 1 of ribose and deoxyribose

Identify the statements that describe a chromosome. ( can be more than one)

  

A.is a linear or circular molecule

B.functions to package, organize, and regulate access to DNA

C.each organism has one

D. acts as the basic unit of heredity

E. is a contiguous piece of DNA

F.may include plasmids

G. codes for a specific protein

H. is the largest molecules in the cell

Answer 1

Answer. DNA contains pyrimidine thymine is correct because DNA has both purine (adenine and guanine) and pyrimidine (thymine and cytosine). While the bases are attached covalently to sugars,

DNA contain Deoxyribose where 2' is a deoxy group

Answer. Sugars are connected with 3' -5' is correct for both DNA and RNA. While DNA is not hydrolysed in alkaline solution as it does not contain 2'OH group. Bases composition B and C are incorrect because RNA is single stranded and bases percentage will vary.

Answer. Nucleoside do not contain phosphate group , it can contain either deoxyribose (in case of DNA) and ribose sugar (in case of RNA). C is incorrect as it doesn't have phosphate group. While D and E are correct as nucleoside is found in both DNA and RNA also bases are attached to Carbon 1 of ribose or deoxyribose

Answer chromosome is a linear or circular molecule it also act as the basic unit of heredity, it is largest molecules in the cell. , while each organism can have variable number of chromosome, also chromosome and plasmid are different entity. Chromosome is not contiguous piece of DNA. Also it codes for many protein not a specific protein.