MCQ

Question 1

Simplest virus

Answer 1

Filamentous

Question 2

What component do enveloped virus have?

Answer 2

Isometric

Question 3

Common receptor to virus is said to be

Answer 3

Low affinity receptor

Question 4

Viral capsid binds to?

Answer 4

High affinity receptor

Question 5

Co receptors virus binds to are

Answer 5

CCR5
CXCR4

Question 6

Transformation

Answer 6

• naked DNA uptake by bacteria, picked up by adjacent

Question 7

Transduction

Answer 7

• Bacterial DNA transfered by phages (virus)

Question 8

Conjugation

Answer 8

• Structural connection between bacterial cells
• passing of plasmid

Question 9

Pan genome

Answer 9

Elements found on one or more strains
Not all strains

Question 10

Core genome

Answer 10

Present in all genome

Question 11

Monotrichous

Answer 11

single flagellum

Question 12

Lophotricous

Answer 12

Multiple
same end

Question 13

Amphitrichous

Answer 13

Single Flagellum each end

Question 14

Petrichous

Answer 14

numerous flagellum around structure

Question 15

Atrichous

Answer 15

No flagellum

Question 16

Bacteriophage components

Answer 16

• capsid
• tail
• adsorption apparatus

Question 17

Virulent phages enter

Answer 17

Lytic cycle

Question 18

Temperate phages enter

Answer 18

Lysogenic

Question 19

How does phage viral release take place from bacteria

Answer 19

-endolysins
-holins

Question 20

• Endolysins degrade

Answer 20

Peptidoglycan

Question 21

What protein cause conformation change

Answer 21

Spanin

Question 22

What signalling molecule decides lysogenic/ lytic cycle?

Answer 22

Arbitrium

Question 23

Low arbitrium

Answer 23

Lytic cycle

Question 24

High arbitrium

Answer 24

Lysogenic

Question 25

Phage viral DNA neither replicates or integrates, which cycle?

Answer 25

Pseudo-lysogenic stage

Question 26

How is capsid of phage froms (encapsulated)

Answer 26

1. Terminase binds viral genome concatemer 1. Terminase - dna binds procapsid portal 1. DNA translocation (ATP-ADP) 1. Contamer cleavage + packaging completion

Question 27

What is burst size

Answer 27

Number of phages produced by infected host cell

Question 28

Shift between latent and eclispe period determined with?

Answer 28

Chloroform

Question 29

Bacteria resistance mechanisms from phage

Answer 29

1. Preventing virus adsorptions 2. prevent virus entry 3. cutting virus nucleuc acid 4. abortive infection 5. CRISPR-CAS

Question 30

Preventing virus adsorption

Answer 30

- Bacteria mutates receptor - >blocking virus receptor - bacteria changes porins in the outer membrane

Question 31

Most important mechanism for virus DNA entry into bacteria

Answer 31

**Superinfection exclusion mechanism**

Question 32

Phage T4 is prevented entry by which bacterial proteins?

Answer 32

- Imm - Sp

Question 33

Imm bacterial protein

Answer 33

- redirect viral DNA outside of cell

Question 34

Sp bacterial protein

Answer 34

Stops activity of degredation of T4 lysozyme

Question 35

What enzyme does bacteria use to modify its DNA?

Answer 35

- Methyltrasnferase - Adds methyl

Question 36

Which enzyme cleave unmethylated bits of DNA?

Answer 36

- Restriction enzymes - >restriction endonucleases

Question 37

What viral protein inhibits restriction enzyme?

Answer 37

**OCR protein** >mimics DNA >releases into bacterial cell before it hijacks

Question 38

2 ways Abortive infection occurs

Answer 38

- membrane puncturing - self toxificatin

Question 39

2 enzymes in membrane puncturing

Answer 39

1. Rex B 2. Rex A

Question 41

Obligate

Answer 41

Needs host to survive

Question 42

Opporutunistic

Answer 42

Not parasitic, but can make use of opportunity

Question 44

Amatoxins

Answer 44

- inhibit RNA polymerase II