Genomics

Question 1

What is a virus and what does it consist of?

Answer 1

A virus is an infectious particle with a bit of nucleic acid wrapped in a protein coat called a capsid and, in some cases, a membrane envelope.

Question 2

What are the viruses that infect bacteria known as?

Answer 2

Bacteriophage.

Question 3

What is the only goal of a virus?

Answer 3

A virus’ only goal is to replicate, and cannot do that on its own – needs a host

Question 4

How does the viral DNA become part of the host’s DNA?

Answer 4

1. The virus attaches itself to the bacterial cell and injects its DNA.
2. Phage DNA circularizes

Lytic cycle: the new phage and proteins are synthesized, then they assemble into new phages and burst the cell releasing the phages.

Lysogenic cycle: The phage inserts its DNA into the bacteria’s chromosome, it is then called a prophage. The bacteria replicates and copies the prophage at every stage.

Question 5

What are the 3 ways bacteria can transfer DNA?

Answer 5

1. Transformation: Foreign DNA inserts itself into the chromosome of the host.
2. Transduction: Fragment of DNA from a former phage host is inserted
3. Conjugation: The donor cell and recipient cell form a mating bridge and transfer DNA

Question 6

What is the ability of a donor E. coli cell to carry out conjugation?

Answer 6

The ability of a donor E. coli cell to carry out conjugation is usually due to a specific piece of DNA called the F factor (F for fertility).

An F factor can exist as a plasmid.

Question 7

Why do R plasmids pose big problems to human medicine?

Answer 7

R plasmids pose serious problems for human medicine by carrying genes for enzymes that destroy antibiotics.

Question 8

What are the applications of gene modifications?

Answer 8

1. A gene is used to alter bacteria for cleaning up toxic waste.
2. A gene for pest resistance is inserted into plants.
3. Insulin is given to diabetics
4. A protein is used to dissolve blot clots in heart attack therapy.

Question 9

Can existing genes be edited?

Answer 9

yes.
Researchers introduce Cas9 protein and guide RNA.

The Cas9/guide RNA complex binds to the target DNA sequence in the nucleus.

Next, the Cas9 protein cuts both DNA strands.

A normal copy of the gene serves as a template for repair enzymes to edit the cut in the target gene, resulting in a corrected nucleotide sequence

Question 10

What is an application of CRISPR-Cas9 system?

Answer 10

1. Xenotransplantation, which involves taking parts of bovine or porcine organs and transplanted into humans, in order to minimize graft rejection.

Question 11

What cells are used for for eukaryotic and prokaryotic organisms?

Answer 11

prokaryotic: E.coli
eukaryotic: Yeast

Question 12

Give an example of recombinant genes being mass produced.

Answer 12

A recombinant gene for human antithrombin (a clotting factor) inserted into goat genome and can be harvested in the milk

Question 13

How are we able to make organisms produce the proteins of different organisms?

Answer 13

This fact showcases the conservation of cell machinery across prokaryotic and eukaryotic organisms, resulting in similar genetic mechanisms

Question 14

What are the uses of DNA technology?

Answer 14

1. Treating diseases: insulin is injected in diabetic patients who cannot produce their own. Before, insulin was harvested from pigs but that led to allergic reactions.
2. Diagnosing diseases: PCR
3. Preventing diseases: Different recombinant organisms can also be used for vaccine production (ex: Hepatitis B vaccine in bacteria, flu vaccines are produced in embryonated chicken eggs)

Question 15

What is an example of a GMO plant?

Answer 15

Golden rice uses daffodil genes to boost it’s beta-carotene levels.

Question 16

What virus can insert themselves into human genomes?

Answer 16

Retrovirus