What would be the effect on the PCR reaction if any of the following circumstances arose: 1) there are no primers in the reaction, 2) there are no dNTPs in the reaction, 3) there is no Taq polymerase in the reaction?

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#Question id: 40487

#Applied Microbiology

Match the Chemical/Term (List I) with its description or impact (List II).

List I (Term)	List II (Description)
A. CFCs	1. Replacement for CFCs; zero ODP but high GWP.
B. HFCs	2. Used in fire extinguishers; contains Bromine which depletes ozone.
C. Halons	3. Major ODS used in refrigerants; releases Chlorine.
D. UV-B	4. Radiation absorbed by the ozone layer; causes skin cancer.

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#Question id: 40488

#Applied Microbiology

The water activity (aw) of pure water is equal to:

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#Question id: 40489

#Applied Microbiology

Which class of microorganisms is specifically adapted to grow in environments with very low water activity (high salt concentration)?

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#Question id: 40490

#Applied Microbiology

Read the following statements regarding water availability:

Statement I: Water activity (a_w) is defined as the ratio of the vapor pressure of the solution to the vapor pressure of pure water.

Statement II: Most pathogenic bacteria require a water activity (a_w) greater than 0.90 for growth.Which of the options is correct?

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#Question id: 40491

#Applied Microbiology

Assertion (A): Foods like jams and jellies rarely undergo bacterial spoilage even at room temperature.

Reason (R): High concentrations of sugar reduce the water activity (a_w), creating hypertonic conditions that dehydrate bacteria (plasmolysis).

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#Question id: 40492

#Applied Microbiology

Which molecule on the surface of a Helper T lymphocyte (Th) is responsible for recognizing antigens presented by MHC-II?