Usually, how many nucleotides are found in a tRNA molecule?
tRNA molecules are relatively small, typically consisting of about 73 to 93 nucleotides. This compact size allows them to fit into the ribosome during translation.
Question 92 of 668
📘 CLASS XII
During DNA replication, the primers are chemically?
The primers used to initiate DNA synthesis in vivo are short strands of RNA synthesized by the enzyme Primase. They provide the free 3-prime hydroxyl group needed by DNA polymerase.
Question 93 of 668
📘 CLASS XII
The unwinding of DNA creates a Y-shaped structure called?
The separation of the two DNA strands creates a Y-shaped region where the helix is being unwound and new strands are being synthesized. This structure is called the replication fork.
Question 94 of 668
📘 CLASS XII
Which of the following is a non-sense codon?
Non-sense codons are stop codons that do not code for any amino acid. UGA (Opal) is one of the three stop codons.
Question 95 of 668
📘 CLASS XII
In which organisms are transcription and translation not coupled?
In eukaryotes, transcription occurs in the nucleus, and translation occurs in the cytoplasm. The physical separation by the nuclear envelope prevents coupling. In prokaryotes, they happen in the same compartment simultaneously.
Question 96 of 668
📘 CLASS XII
The cap added to the 5-prime end of eukaryotic mRNA is composed of?
The 5-prime cap is a modified guanine nucleotide, specifically 7-methylguanosine, attached via a unique 5-to-5 triphosphate linkage.
Question 97 of 668
📘 CLASS XII
Which scientist proposed the "One gene, One enzyme" hypothesis (related concept)?
Although usually taught in broader genetics, Beadle and Tatum proposed "One gene, One enzyme" (later one gene, one polypeptide), linking genes to protein function.
Question 98 of 668
📘 CLASS XII
Jacob and Monod are famous for elucidating?
Francois Jacob (a geneticist) and Jacques Monod (a biochemist) were the first to elucidate the transcriptional regulation system known as the Lac Operon.
Question 99 of 668
📘 CLASS XII
In the absence of lactose, the repressor binds to the?
When lactose is absent, the repressor protein remains active and binds tightly to the operator region of the operon, physically blocking RNA polymerase from transcribing the structural genes.
Question 100 of 668
📘 CLASS XII
Which human chromosome was the last to be sequenced?
Chromosome 1 is the largest human chromosome and was the last one to be completely sequenced, with the sequence published in May 2006.
