Bacterial Structures

Reverse Transcriptase PCR (RT-PCR) is a molecular diagnostic technique used for detecting RNA-based pathogens. It works by converting RNA into complementary DNA (cDNA) followed by amplification.
Step 1: Understanding RT-PCR usage.
RT-PCR is widely used for detecting a variety of RNA viruses, such as influenza, HIV, hepatitis viruses, and SARS-CoV-2. It is \textit{not} specific only to coronavirus detection.
Step 2: Evaluate options.
Option (A) is correct — RT-PCR detects specific RNA sequences.
Option (C) is correct — RT-PCR cannot distinguish live vs. dead viruses.
Option (D) is correct — the process is RNA → cDNA → amplification.
Thus, (B) is the only incorrect (NOT correct) statement.
Final Answer: (B)

Step 1: Aerobic bacteria.
Aerobic bacteria require oxygen as the terminal electron acceptor. Thus, (i) is correct.
Step 2: Anaerobic bacteria.
Anaerobic bacteria grow without oxygen. They use other compounds (like nitrate, sulfate, CO ), not DO. Thus, (iii) is incorrect.
Step 3: Facultative bacteria.
Facultative bacteria can switch between oxygen (if available) and other acceptors like nitrate/nitrite. Thus, (iv) is correct.
Step 4: Check nitrite for aerobic bacteria.
Aerobic bacteria do not need nitrite as an electron acceptor because they directly use oxygen. Thus, (ii) is incorrect. So, the correct statements are (i) and (iv). Final Answer: