Advertisements
Advertisements
Question
Assertion (A): The backbone of DNA and RNA molecules is a chain consisting of heterocyclic base, pentose sugar and phosphate group.
Reason (R): Nucleotides and nucleosides mainly differ from each other in the presence of phosphate group.
Options
Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.
Advertisements
Solution
Assertion (A) is false, but Reason (R) is true.
Explanation:
The DNA molecule is made up of two strands that spiral around each other like a twisted ladder. Each strand has an alternate backbone of sugar (deoxyribose) and phosphate groups.
APPEARS IN
RELATED QUESTIONS
Write the structure of a nucleoside
Which of the following NOT present in DNA?
(a) adenine
(b) Guanine
(c) Thymine
(d) Uracil
What type of linkage is present in nucleic acids?
Define the following term:
Nucleotide
What are nucleic acids?
Give balanced equations for the following reactions:
Name the nitrogen base residues present in DNA
Which base is present in RNA, but not in DNA?
Write the structures of fragments produced on complete hydrolysis of DNA. How are they linked in DNA molecule? Draw a diagram to show pairing of nucleotide bases in double helix of DNA.
Which of the following contributes to the double helical structure of DNA?
Give a reason for the following observations:
The two strands in DNA are complementary to each other.
