Study Guide for DNA, Transcription, and Translation Quiz

What does it mean when DNA is described as 'antiparallel'?

It means that the two strands of DNA run in opposite directions; one runs 5' to 3' and the other runs 3' to 5'.

What are the two types of chromosomes found in prokaryotes and eukaryotes?

Prokaryotes have circular chromosomes, while eukaryotes have linear chromosomes.

What are the base pairing rules in DNA?

A pairs with T and G pairs with C.

What is the role of helicase in DNA replication?

Helicase unzips the DNA strands.

In what direction does DNA synthesis occur and why?

DNA is synthesized in the 5' to 3' direction because DNA polymerase can only add nucleotides to the hydroxyl end of the last nucleotide.

What does 'semi-conservative' mean in the context of DNA replication?

It means that each new DNA molecule consists of one original strand and one new strand.

What distinguishes the leading strand from the lagging strand during DNA replication?

The leading strand moves toward the opening of the DNA fork and is synthesized continuously, while the lagging strand moves away and must be synthesized in segments.

What is the function of spliceosomes in RNA processing?

Spliceosomes cut out introns from the mRNA transcript but keep exons.

What occurs during the transcription process?

RNA polymerase synthesizes a single stranded mRNA strand using the DNA template.

What is added to the 3' end of mRNA during processing, and what is its function?

A poly-A tail is added to stabilize the mRNA and help it exit the nucleus.

How does translation begin?

Translation begins with the attachment of mRNA to the ribosome and the start codon (AUG) signaling the initiator tRNA.

What is the genetic code's consistency across organisms?

The genetic code is the same in all living organisms.

What is the difference in transcription and translation processes between prokaryotes and eukaryotes?

Prokaryotes can perform transcription and translation simultaneously in the cytoplasm, while eukaryotes perform these processes separately with RNA processing occurring in the nucleus.

What are codons and where are they found?

Codons are three-nucleotide sequences on mRNA that specify amino acids.

What is the role of tRNA in translation?

tRNA matches its anticodon with the codon on mRNA to bring the corresponding amino acid during protein synthesis.

What are the three key phases of translation?

Initiation, elongation, and termination.

What happens during the termination phase of translation?

Translation terminates when a stop codon is reached, signaling the end of amino acid addition.