AP Bio Chapter 14-15 Test

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this?

Degeneracy

Which molecule in the central dogma can be compared to a disposable photocopy of a book kept on reserve in the library?

mRNA

Which subunit of the E. coli polymerase confers specificity to transcription?

σ

How many nucleotides make up a codon?

3

How many nucleotides are in 12 codons?

36

In prokaryotes, ribosomes are found in/on the what?

Cytoplasm

What is the flow of information for the synthesis of proteins according to the central dogma?

DNA to mRNA protein

Which of the following features distinguishes eukaryotic transcription from bacterial transcription?

Eukaryotic transcription and translation do not take place at the same time.

What is the major challenge in the production of our in a in eukaryotes compared to prokaryotes?

Exporting the MRNA across the nuclear membrane

Explain the initiation of transcription in prokaryotes. Include all the proteins involved.

In prokaryotes the polymerase is composed of five polypeptide subunits two of which are identical.

At what stage of transcription of a eukaryotic gene would TFII factors be active in?

Initiation

What is often the first amino acid added to the polypeptide chain?

Methionine

If mRNA is Complementary to the DNA template strand in the DNA template strand is complementary to the DN a non-template strand why are base sequences of MRNA and the DNA a non-template strand not identical. Could they ever be?

No, they cannot be identical because the T nucleotide in do you in a is replaced with you nucleotide in RNA and AUG is the start codon.

Which of the following molecules doesn't contain genetic information?

Protein

What process transfers hereditable material to the next generation?

Replication

In your own words, describe the difference between dependent and independent termination of transcription in prokaryotes.

Row dependent termination is controlled by row proteins in the polymerase stalls near the end of the gene at a run of G nucleotides on the DNA template. In row independent termination, when the polymerase encounters a region which the C Dash G nucleotides the MRNA forms into a hairpin loop that causes the polymerase to stall.

What is the main structure that differentiates between dependent and independent termination in prokaryotes?

Row independent termination involves the formation of a hairpin

Which feature of promoters can be found in prokaryotes and eukaryotes?

TATA box

What characteristic of the genetic code points to a common ancestry for all organisms?

The genetic code is almost universal

Which step in the transcription of eukaryotic RNA different the most from its prokaryotic counterpart?

The initiation step in eukaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA strand is different as histones are involved

You sequence a gene of interest and isolate the matching RNA. you find that the mRNA is considerably shorter than the experimental DNA sequence. Why is that?

The processed mRNA is shorter because introns were removed.

What are introns?

Untranslated DNA sequence of a gene

the sequence that signals the end of transcription

terminator

Where are the RNA components of ribosomes synthesized?

Nucleolus