Question

Why is RNA single-stranded, unlike DNA?

a. RNA is less stable than DNA.
b. RNA has a hydroxyl group at the 2' position of the ribose sugar.
c. RNA is more prone to mutagenic attacks.
d. All of the above.

Why is DNA double-stranded, in contrast to RNA?
a. DNA is more stable than RNA.
b. DNA provides protection for nitrogenous bases.
c. DNA allows for proofreading during replication.
d. All of the above.

What is the key structural difference between DNA and RNA?
a. Presence of hydroxyl group
b. Nitrogenous base composition
c. Phosphate linkage
d. Helical geometry

How do dsRNA and ssRNA function differently in biological systems?
a. dsRNA is a signal of foreign elements, while ssRNA is a common cellular component.
b. dsRNA is more stable than ssRNA.
c. ssRNA is prone to mutagenesis.
d. Both a and b.

What is the primary role of RNA in cellular processes?
a. RNA carries genetic information to the nucleus.
b. tRNA transfers amino acids to the mRNA.
c. rRNA translates information in the ribosome.
d. All of the above.

How does DNA contribute to the expression of traits in living organisms?
a. DNA directly produces proteins.
b. RNA determines which traits are activated or deactivated.
c. Genes in DNA encode information for protein synthesis.
d. DNA regulates energy production in cells.

Why is DNA preferred over RNA as genetic material?
a. DNA is more chemically stable than RNA.
b. DNA has a hydroxyl group at the 2' carbon.
c. DNA allows for self-repair during replication.
d. All of the above.

Which characteristic of DNA provides information security?
a. Double-stranded structure
b. Presence of thymine instead of uracil
c. Hydroxyl group at the 2' position
d. Helical geometry

What is the consequence of the hydroxyl group in RNA's conformationally flexible regions?
a. It enhances the stability of the RNA molecule.
b. It allows for proofreading during replication.
c. It can chemically attack adjacent phosphodiester bonds.
d. It prevents RNA from mutagenic attacks.

How does the double-stranded configuration of DNA contribute to information protection?
a. It exposes nitrogenous bases to the cellular environment.
b. It provides proofreading capabilities during replication.
c. It shields nitrogenous bases within the helical structure.
d. It increases the susceptibility of DNA to mutagenesis.

Answer 1

RNA is single-stranded with a ribose sugar backbone and contains uracil in place of thymine. DNA is double-stranded with a deoxyribose sugar backbone, and its structure safeguards genetic information. The structural differences between DNA and RNA underpin their distinct roles in protein synthesis and genetic information storage.

Step-by-step explanation:

Differences Between DNA and RNA

The principal difference between DNA and RNA is that RNA is single-stranded while DNA is double-stranded. Additionally, the sugar present in the backbone of RNA is ribose, which has an extra hydroxyl group compared to the deoxyribose in DNA. This structural variation of an extra oxygen atom on the ribose sugar makes RNA less stable chemically, lending itself to temporary functions such as protein synthesis, for which RNA plays a critical role.

RNA nucleotides contain three of the same nitrogenous bases as DNA (adenine, cytosine, and guanine), while the fourth base is uracil (U) in place of thymine (T). The presence of uracil instead of thymine in RNA and the double-stranded nature of DNA contribute to the different functions and stability of these molecules. In RNA, uracil pairs with adenine during the process of protein synthesis.

RNA's structure allows it to fold upon itself, forming intricate three-dimensional shapes necessary for its function. In contrast, DNA's double-stranded helical structure serves to protect genetic information. A key role of RNA in cells is to interpret the genetic code from DNA and direct the synthesis of proteins, which determine the phenotype of organisms.