review part 1

Question 1

What does the Baltimore system classify viruses by? What would lead to higher mutation rates based on this?

Answer 1

Based on genome type and replication strategy:
- (+) ssRNA and (-) ssRNA
- dsDNA, ssDNA, dsRNA

Small RNA genome viruses lead to higher mutation rates due to RNA pol limitations

Question 2

Double-stranded DNA genome DNA viruses use the ________ to transcribe their genome into ______ and replicate their genome

Answer 2

Double-stranded DNA genome DNA viruses use the HOST CELL MACHINERY to transcribe their genome into mRNA and replicate their genome

Question 3

Single stranded DNA genomes, describe their replication

Answer 3

The ssDNA can either be (+) or (-)

dsDNA is produced from the ssDNA, and is then transcribed by host machinery to make mRNA, and replicated by host machinery, after which the strands are seperated

Question 4

Describe how retroviruses function

Answer 4

Reverse transcribe their RNA genome into ssDNA, which is then used to make dsDNA.

The dsDNA is integrated into the host genome and transcribed to make mRNA and new genomes

Question 5

What is T4 phage?

Answer 5

A lytic phage that always causes lysis, and its dsDNA replication involves a complex process of protein-protein interactions

Question 6

Briefly describe Influenza virus

Answer 6

• an enveloped (-) ssRNA virus that makes (+) ssRNA in the nucleus
• the (+) ssRNA is translated and used to make (-) ssRNA, which is then packaged into viral proteins before the virus buds out of the host

Question 7

Describe the features of SARS-Cov-2

Answer 7

• enveloped (+) ssRNA virus, its genome can be translated

Question 8

Briefly describe HIV

Answer 8

a type of retrovirus, HIV uses reverse transcriptase to synthesize dsDNA using the + ssRNA genome as a template.

The dsDNA is integrated into the host genome, and mRNA is produced and translated to make viral proteins. The virus also produces ssRNA, which assembles with proteins to make new virions

Question 9

What step of translation do antibiotics target?

Answer 9

The elongation step

Question 10

How do antibiotics work? (general)

Answer 10

In different ways such as preventing tRNA delivery, blocking peptide bond formation, blocking translocation, and causing misreading of mRNA

Question 11

T or F: Mutations to HIV protease gene decrease resistance to protease inhibitors

Answer 11

False

Mutations to HIV protease gene INCREASE resistance to protease inhibitors

Question 12

Describe how HIV-AIDS functions

Answer 12

• HIV targets CD4 T cells, leading to immune deficiency and AIDS
• chronic activation of immune response can lead to activation-induced cell death

Question 13

Describe oncogenic viruses

Answer 13

• Proto-oncogenes are genes involved in cell growth and differentiation; mutations or changes can lead to uncontrolled cell growth (cancer)
• retroviruses can integrate into host chromosomes and convert proto-oncogenes into oncogenes, leading to cancer

Question 14

Vaccines can be made from _____ or ______ microbes or ______ of microbes

Answer 14

Vaccines can be made from ATTENUATED or DEAD microbes or COMPONENTS of microbes

Question 15

Are probiotics live micro-organisms?

Answer 15

Yes

Question 16

Does RNAse L degrade viral mRNAs and cellular mRNAs, or only viral mRNAs?

Answer 16

both