Molecular Basis of Inheritance Chapter-Wise Test 8

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which of the following statements about DNA replication is correct?

It occurs only in the 3' to 5' direction
It is conservative in nature
It requires an RNA primer for initiation
It takes place in the cytoplasm of eukaryotic cells
3

DNA replication requires an RNA primer synthesized by primase to initiate the process.

Which of the following is a correct feature of the genetic code?

It is ambiguous.
It is overlapping.
It is degenerate.
It varies between organisms.
3

The **genetic code is degenerate**, meaning multiple codons can code for the same amino acid.

Which of the following statements about RNA is correct?

RNA contains thymine instead of uracil
RNA is always double-stranded
RNA is less stable than DNA
RNA has deoxyribose sugar
3

RNA is less stable than DNA because it has a reactive hydroxyl (-OH) group at the 2' position of its ribose sugar.

Which of the following is true about exons?

They are removed during splicing
They do not code for proteins
They are coding regions of genes
They are present only in prokaryotic cells
3

Exons are the coding regions of genes that remain in mRNA after splicing and are translated into proteins.

Which molecule is involved in post-transcriptional gene silencing?

mRNA
miRNA
rRNA
tRNA
2

miRNA (microRNA) is involved in post-transcriptional gene silencing by binding to target mRNA and preventing its translation.

Which of the following is correct about stop codons?

They code for amino acids.
They signal the termination of translation.
They initiate transcription.
They bind to DNA polymerase.
2

Stop codons **signal the termination of translation**, ensuring the newly synthesized protein is released from the ribosome.

Which of the following is incorrect about RNA?

RNA is usually single-stranded.
RNA contains uracil instead of thymine.
RNA has deoxyribose sugar.
mRNA carries genetic information from DNA to the ribosome.
3

RNA contains **ribose sugar, not deoxyribose**.

Which component of the human genome consists of the highest percentage?

Protein-coding genes
Repetitive sequences
Regulatory elements
Non-coding RNAs
2

Repetitive sequences make up a large portion of the human genome, while protein-coding genes constitute less than 2%.

Which of the following RNA types has catalytic activity?

mRNA
tRNA
rRNA
snRNA
3

rRNA (ribosomal RNA) has catalytic activity, helping form peptide bonds during protein synthesis.

Which of the following correctly describes the role of a poly-A tail?

It helps in DNA replication.
It stabilizes mRNA and prevents degradation.
It is required for transcription initiation.
It is found at the 5' end of mRNA.
2

The **poly-A tail stabilizes mRNA and prevents degradation**, aiding in efficient translation.

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