Exploring DNA and RNA Structures

What is the primary structural difference between DNA and RNA?

• DNA contains ribose sugar, while RNA contains deoxyribose sugar.

• DNA is double-stranded, while RNA is single-stranded.

• DNA contains uracil, while RNA contains thymine.

• DNA is found only in the nucleus, while RNA is found only in the cytoplasm.

Answer explanation

The primary structural difference is that DNA is double-stranded, providing stability, while RNA is single-stranded, allowing for more versatility in function and structure.

Which of the following is not a type of RNA?

• mRNA

• tRNA

• rRNA

• dRNA

Answer explanation

dRNA is not a recognized type of RNA. The main types of RNA are mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA), which play crucial roles in protein synthesis.

What is the main function of DNA in the cell?

• To carry amino acids to the ribosome.

• To store and transmit genetic information.

• To catalyse the formation of peptide bonds.

• To form the core of the ribosome's structure.

Answer explanation

The main function of DNA is to store and transmit genetic information, which is essential for the development, functioning, and reproduction of all living organisms.

Tags

NGSS.HS-LS3-1

Which of the following bases is found in RNA but not in DNA?

• Adenine

• Thymine

• Uracil

• Cytosine

Answer explanation

Uracil is a nitrogenous base found in RNA, replacing thymine, which is present in DNA. Therefore, uracil is the correct answer as it is unique to RNA.

How does the sugar component differ between DNA and RNA?

• DNA contains ribose, while RNA contains deoxyribose.

• DNA contains deoxyribose, while RNA contains ribose.

• Both DNA and RNA contain ribose.

• Both DNA and RNA contain deoxyribose.

Answer explanation

DNA contains deoxyribose, which lacks one oxygen atom compared to ribose found in RNA. This structural difference is key in distinguishing the two nucleic acids.

Which type of RNA is responsible for bringing amino acids to the ribosome during protein synthesis?

• mRNA

• tRNA

• rRNA

• snRNA

Answer explanation

tRNA, or transfer RNA, is responsible for bringing amino acids to the ribosome during protein synthesis. It matches the amino acids to the corresponding codons on the mRNA, facilitating the assembly of proteins.

What is the role of rRNA in the cell?

• It carries genetic information from DNA to the ribosome.

• It catalyses the formation of peptide bonds.

• It forms the core of the ribosome's structure and catalyses protein synthesis.

• It processes and modifies mRNA.

Answer explanation

rRNA is essential as it forms the structural core of ribosomes and plays a crucial role in catalyzing protein synthesis by facilitating the formation of peptide bonds between amino acids.

Which type of RNA is involved in the splicing of pre-mRNA?

• mRNA

• tRNA

• rRNA

• snRNA

Answer explanation

snRNA, or small nuclear RNA, plays a crucial role in the splicing of pre-mRNA by forming complexes with proteins to create spliceosomes, which remove introns from the pre-mRNA transcript.

What is the function of tRNA in protein synthesis?

• It carries genetic information from DNA to the ribosome.

• It forms the core of the ribosome's structure.

• It brings amino acids to the ribosome and matches them to the coded mRNA message.

• It catalyses the formation of peptide bonds.

Answer explanation

tRNA's primary function is to bring amino acids to the ribosome and match them to the corresponding codons on the mRNA. This process is essential for translating the genetic code into a functional protein.

Which of the following statements is true about the comparison between DNA and RNA?

• Both DNA and RNA are double-stranded molecules.

• DNA is more stable than RNA due to the presence of thymine.

• RNA is more stable than DNA due to the presence of uracil.

• Both DNA and RNA contain the same types of nucleotides.

Answer explanation

DNA is more stable than RNA primarily due to the presence of thymine, which is less reactive than uracil found in RNA. This stability is crucial for DNA's role in long-term genetic information storage.