Lecture 14

Question 1

Can viruses reproduce?

Answer 1

Yes and No - they can not reproduce unless inside a cell

Question 1

Can viruses utilize energy?

Answer 1

No.

Question 2

Can viruses carry out chemical reaction?

Answer 2

No.

Question 3

Can viruses engage in mechanical activities?

Answer 3

No

Question 4

Can viruses respond to stimuli?

Answer 4

No

Question 5

Are viruses capable of self-regulation?

Answer 5

No

Question 6

Can viruses evolve?

Answer 6

Yes

Question 7

Are viruses cells?

Answer 7

No

Question 8

What are viruses?

Answer 8

Macromolecular packages that can function and reproduce only within living cells

Question 9

What are viruses outside of cells?

Answer 9

Inanimate particles called virion

Question 10

What is a virion made of?

Answer 10

Small amount of DNA or RNA that encodes a few hundred of genes

A protein capsule called capsid

Question 11

What is the size of a virus?

Answer 11

Roughly 1000 nanometer

Question 12

What is one of the first viruses to be characterized?

Answer 12

TMV was one of the first viruses to be characterized

Question 13

What is the Baltimore Classification?

Answer 13

Categorizes viruses based on the type of genome (RNA/DNA) and their method of replication.

Question 14

What is HIV an example of?

Answer 14

A retrovirus (A RNA virus that can insert a copy of its genome into the DNA of a host cell to cause AIDS)

Question 15

What is Hepatitis B a member of?

Answer 15

The hepadnavirus family (DNA type), which affects human liver and causes serious infections.

Question 16

What is Ebola virus apart of?

Answer 16

The filoviruses family- encodes their genome in the form of single stranded negative - sense RNA.

Question 17

What are Adenoviruses?

Answer 17

A group of viruses that can cause respiratory illnesses (bronchitis, pneumonia) or conjunctivitis (an infection of the eye)

Question 18

What is a Bacteriophage?

Answer 18

A virus that infects and replicates within archaea and bacteria

Question 19

How many virus species have been formally described?

Answer 19

4,985

Question 20

What have bacteria evolved as a way to battle the continuous attacks from bacteriophages?

Answer 20

An immune like system called the CRISPR-Cas

Question 21

What is a narrow host range?

Answer 21

Human cold and influenza viruses that infect epithelial cells of human respiratory system (most common type)

Question 22

What is a wide host range?

Answer 22

rabies, that can infect cells in dogs, humans, bats and raccoons

Question 23

What happens once a virus is inside a cell?

Answer 23

It hijacks cellular machinery to synthesize nucleic acids (DNA/RNA) and proteins.

Question 24

What are the two main types of viral infection?

Answer 24

Lytic and Non-Lytic

Question 25

What is a lytic virus?

Answer 25

Production of virus particles ruptures (and kills) cell (e.g, influenza, rabies)

Question 26

What is a non-lytic virus (lysogenic)?

Answer 26

Viral DNA is inserted in host genome, the infected cell can survive, often with impaired function (HIV, Chicken Pox)

Question 27

Papovavirus

Answer 27

A large family of viruses that includes the human papilloma virus (HPV)

Question 28

What does the rabies virus have?

Answer 28

An enveloped single stranded RNA genome

Question 29

What does the RNA genome encode of the rabies virus?

Answer 29

Five genes: nucleoprotein (N), phospoprotein (P), Matrix protein (M), glycoprotein (G) and viral RNA polymerase (L)

Question 30

How many genotypes of rabies virus are known?

Answer 30

7 genotypes

Question 31

What does Zika virus cause?

Answer 31

A large number of infants born with microcephaly

Question 32

How is Zika Virus transmitted?

Answer 32

Primarily by mosquitoes, but also through sexual contact or blood transfusion

Question 33

What is microcephaly?

Answer 33

A condition where the head circumference is smaller than normal Affects early brain development causing delayed motor and speech functions, intellectual disability, seizures, hyperactivity, etc.

Question 34

How does Zika Virus get transmitted?

Answer 34

It crosses the placental barrier by targeting trophoblasts and macrophages If infection of the fetus occurs during the period of neurogenesis, the survival of neural progenitor cells (NPCs) can be affected

Question 35

How do RNA vaccines work?

Answer 35

They trick the body's cells into producing a fragment of a virus, an antigen, from an RNA template.

Question 36

What is a strategy to make RNA vaccines more effective at lower doses?

Answer 36

Incorporate the instructions for assembling a replicase, which can make lots of copies of the RNA template for producing antigens.