Lec1

Question 1

List Infectious agents

Answer 1

Bacteria- fungi- viruses- protozoa- helminths

Question 2

Some infections are communicable
T/F?

Answer 2

F, Almost all

Question 3

After the transfer of pathogen to the body apparent symptoms and signs appear after some time.

Answer 3

Incubation period

Question 4

Infections that don’t result in clear symptoms

Answer 4

Inapparent , latent, subclinical infection

Question 5

Dangerous sources of infections to other threatening public health

Answer 5

Chronic carriers

Question 6

Infection occurring at a persistent low level in certain geographic area

Answer 6

Endemic infection

Question 7

Infection occurring frequently than usual for some time in certain geographical area

Answer 7

Epidemic infection

Question 8

Infection occurring in worldwide distribution for some time

Answer 8

Pandemic infection

Question 9

Waxy cell wall of Mycobacterium tuberculosis has high con. of lipids called

Answer 9

Mycolic acids

Question 10

Resist the diffusion of drugs abd disinfectant inside cell

Answer 10

Mycolic acids

Question 11

Capsule Limits the ability of phagocytes to engulf bacteria because negative changes on capsule repel positively charged cell membrane.
T /F?

Answer 11

F, negatively

Question 12

Motile enterobacteria like E.coli causes

Answer 12

Urinary tract infections.

Question 13

Links the donor and recipient bacteria during conjugation to Facilitate the exchange of virulence gens

Answer 13

Sex pilus

Question 14

• Resistance to antibiotics
• Resistance to UV
• Resistance to heavy metals
• Production of exotoxins
• Production of becteriocins

Answer 14

Plasmids

Question 15

Example of bacteriocins useful in treating antibiotics Resistance bacteria

Answer 15

• Colicins made but E.coli
• pyocins made by P.aeruginosa

Question 16

short DNA sequences of inverted repeats at each end

Answer 16

Domain 1

Question 17

Transposase gene that mediates the excision and integration processes by expression of transposase enzyme

Answer 17

Domain 2

Question 18

Repressor gene that regulates the expression of transposase gene and gene 4

Answer 18

Domain 3

Question 19

Drug resistance gene or toxin production gene

Answer 19

Domain 4

Question 20

replicate and insert the new copy into another site

Answer 20

Replicative transpsons

Question 21

excised from their site without replicating and then inserted into new site

Answer 21

Direct transposons

Question 22

Medical significance of transposons

Answer 22

1. Transfer drug resistant enzymes or toxins
2. Cause mutation in gene

Question 23

Medical concerns of spores

Answer 23

1. Responsible for resistance of pathogenic bacteria to heat, radiation, chemical.
2. Resistance facilitates survival and spread of bacteria between people.

Question 24

Where dipicolinic acid, a calcium ion chelator found?

Answer 24

In spores

Question 25

Not all bacteria seen by Gram stain T/F?

Answer 25

T

Question 26

Identification of several pathogens is based on fermentation of....

Answer 26

Sugars

Question 27

Ferment lactose

Answer 27

E.coli

Question 28

When sugar fermented phenol red (pH indicator) turns

Answer 28

Yellow

Question 29

Classification of medically bacteria

Answer 29

1. Rigid cell walls 2. Flexible cell walls 3. Without cell walls

Question 30

Classification of medically bacteria

Answer 30

1. Rigid cell walls 2. Flexible cell walls 3. Without cell walls

Question 31

Capable of growing on artifical media in absence of human or animal cells

Answer 31

Bacteria with rigid cell walls ( free living bacteria )

Question 32

Are obligate intracellular parasites and can grow only within human or other animal cell

Answer 32

Bacteria with rigid cell walls ( non living bacteria )

Question 33

Neisseria gonorrhooeae don't ferment maltose T/F?

Answer 33

F, ferment