Biology Central Dogma and Gene Structure

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Questions and Answers

What role does the promoter region play in DNA manipulation?

It drives transcription of the insert DNA. (correct)

It codes for antibiotic resistance in bacteria.

It provides a site for restriction enzymes to cut DNA.

It allows for the selection of plasmids containing DNA.

Which of the following statements accurately describes a selectable marker?

It allows differentiation of transformed organisms. (correct)

It is involved in the amplification of DNA.

It is used only in eukaryotic organisms.

It is typically a gene for a growth hormone.

In the context of a plasmid, what is the function of the primer binding sites?

To facilitate the amplification or sequencing of DNA. (correct)

To allow insertion of the insert DNA.

To promote the expression of the selectable marker.

To provide locations for restriction enzyme recognition.

What can influence the expression levels driven by a promoter region?

Specific growth conditions or inducers. Signup and view all the answers

How does the insert DNA relate to the overall function of the plasmid?

It is the foreign DNA that the plasmid carries and expresses. Signup and view all the answers

What is the role of the lacZ’ region in recombinant DNA technology?

It allows for the identification of plasmids with an insert. Signup and view all the answers

Which statement is true about strains that have the modified lacZ?

They can only produce a functional enzyme with a specific plasmid. Signup and view all the answers

What limitation does the Polymerase Chain Reaction (PCR) face?

It requires knowledge of the DNA sequence to be amplified. Signup and view all the answers

How does the presence of the lacZ’ in the cloning vector affect bacterial colonies?

It leads to blue coloration if the plasmid has no insert. Signup and view all the answers

What is the significance of the deleted lacZ’ region in terms of gene structure?

It prevents the expression of full β-galactosidase unless complemented by a plasmid. Signup and view all the answers

What is the primary function of restriction enzymes in recombinant DNA technology?

To cut DNA at specific sequences Signup and view all the answers

Which of the following best describes the role of ligase in DNA manipulation?

To join DNA fragments together Signup and view all the answers

What are exons and introns in a gene structure?

Regions of DNA that are transcribed into protein-coding regions and non-coding regions, respectively Signup and view all the answers

Which of the following statements is true regarding the transcription process?

The process begins at the promoter region of a gene Signup and view all the answers

In the process of translation, what role does the ribosome play?

It binds to mRNA and synthesizes proteins Signup and view all the answers

Which sequence is known as the universal start codon in protein synthesis?

ATG Signup and view all the answers

What is the purpose of PCR (Polymerase Chain Reaction) in biotechnology?

To amplify specific DNA sequences Signup and view all the answers

Which of the following components is essential for transcription to occur?

RNA polymerase Signup and view all the answers

What role do promoter regions play in gene expression?

They initiate transcription of the gene Signup and view all the answers

How do activators and silencers influence gene regulation?

By enhancing or repressing transcription Signup and view all the answers

Study Notes

Central Dogma

The flow of genetic information from DNA to protein.
Replication is the process of making an identical copy of DNA.
Transcription is the process of making RNA using DNA as a template. The enzyme RNA polymerase is responsible for this process.
Translation is the process of making protein using mRNA as a template. It occurs in the ribosomes.
Start Codon is the ATG, which encodes the amino acid methionine, and there is only one start codon used by all organisms. This codon is the starting point for translation.
Stop Codon signals the end of the protein synthesis.
The direction of transcription and translation is from 5’ to 3’.

Gene Structure

A gene is made of regulatory domains (promoter, activator, silencer, and terminator sequences), and an open reading frame (ORF).
Exons are protein coding sequences within the ORF.
Introns are non-coding sequences within the ORF.

Recombinant DNA Technology

Insert: This is a piece of DNA that has been ligated into a plasmid, usually in the multiple cloning site (MCS) of the vector.
Promoter: A DNA sequence that drives the transcription of the insert DNA leading to the production of recombinant protein.
Selectable markers: These are often antibiotic resistance genes that allow selection of the organism that contains the inserted DNA. In bacteria it would normally be an antibiotic resistance gene.
Primer Binding Sites: Short pieces of DNA where synthesized DNA primers can bind allowing sequencing of the DNA or polymerase chain reaction (PCR) amplification.

Lac Z (β-galactosidase)

The gene Lac Z’ is often used as a selectable marker in bacteria and is placed in the cloning vector.
This gene encodes the first 146 amino acids of β-galactosidase.
The enzyme is only functional if the plasmid carries the Lac Z’ region.
Blue color indicates a functional enzyme, meaning the plasmid does not contain the insert.
White color indicates a non-functional enzyme, meaning the plasmid contains the insert.

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Description

Test your knowledge on the Central Dogma of molecular biology, which details the flow of genetic information from DNA to protein. This quiz also covers important aspects of gene structure, including exons, introns, and the roles of different codons in protein synthesis.