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Lactose absent = gene not expressed (-)

Lactose present = gene is expressed (+)

Lactose absent = gene is expressed (+)

Which of the following inhibits bacterial growth but does not kill bacteria

Lysozyme.

Bacteriostatic agent.

Antiseptic agent.

Bactericidal agent.

Which

of the following is TRUE of a disease carrier?

Some carriers never become sick.

Carriers never develop disease.

Most carriers have a weakened

immune system.

Both a and b are correct.

Which of the following statements about malaria is true

Transmission cannot occur in temperate climates.

The characteristic recurrent fevers are associated

with release of merozoites from RBCs.

P. falciparum

infects only old RBCs and therefore causes

milder disease than other

Plasmodium species.

The disease is currently well controlled in

tropical Africa.

Transmission usually occurs with the bite of a

male

Anopheles mosquito.

The antibody immune response is attributed to the action of

Why

are some bacteria, such as those of the genera Mycobacterium

and

Nocardia, NOT

effectively stained with the Gram stain?

They are

effectively stained with the Gram stain.

They have too much peptidoglycan in

their

cell walls.

They have large amounts of waxy

lipid in their cell walls.

✅

They are very pathogenic bacteria.

If 40 CFU were counted on the plate

1 day after spreading 0.2 ml of a (1/10) bacterial dilution on the plate. How

many bacteria per ml were in the original?

200 CFU/ml

2,000

CFU/ml

50%

4,000

CFU/ml

400 CFU/ml

20,000 CFU/ml

50%

40,000

CFU/ml

Which

of the following statements regarding the polymerase chain reaction is FALSE?

It consists of three steps:

denaturation, priming, and extension.

It can replicate a DNA fragment

flanked by specific sequences.

It can increase the amount of DNA

in a sample.

It utilizes DNA polymerase from

psychrophilic microbes.

✅

Who is usually credited with the discovery of penicillin?

Duchesne

Fleming

Florey and Chain

Ehrlich

A drug that disrupts a microbial function not found in animal cells usually has a higher therapeutic index.

True

False