Thermus aquaticus and PCR

Which statement about Thermus aquaticus is false?
a. The DNA polymerase from T . aquaticus is used in molecular biology for a procedure called polymerase chain reaction (PCR).
b. The DNA polymerase from T . aquaticus is able to withstand very high temperatures.
c. T . aquaticus can survive high temperatures and low pH.
d. T . aquaticus is found in the frozen lakes of Antarctica.

 

Correct Answer:(d) T. aquaticus is found in the frozen lakes of Antarctica.


Explanation

Thermus aquaticus (T. aquaticus) is a thermophilic bacterium known for its ability to survive and thrive at high temperatures. It was first discovered in the hot springs of Yellowstone National Park. The key feature of T. aquaticus is its production of Taq DNA polymerase, which is widely used in molecular biology for the Polymerase Chain Reaction (PCR) due to its thermostability.


🔬 1. Thermus aquaticus and Its Role in PCR

  • T. aquaticus produces Taq polymerase, which remains stable and functional at high temperatures (up to 95°C).
  • PCR involves repeated heating and cooling cycles, which require a heat-stable enzyme for DNA amplification.
  • Most enzymes would denature at high temperatures, but Taq polymerase remains active, making it ideal for PCR.

2. Why the Other Statements Are True

Statement Explanation True/False
(a) The DNA polymerase from T. aquaticus is used in molecular biology for a procedure called polymerase chain reaction (PCR). Taq polymerase is the most commonly used enzyme in PCR because of its heat stability. ✅ True
(b) The DNA polymerase from T. aquaticus is able to withstand very high temperatures. Taq polymerase remains stable at temperatures up to 95°C. ✅ True
(c) T. aquaticus can survive high temperatures and low pH. T. aquaticus is a thermophile and acidophile, tolerating extreme conditions. ✅ True
(d) T. aquaticus is found in the frozen lakes of Antarctica. T. aquaticus thrives in hot springs, not cold environments. ❌ False

🌡️ 3. Why Statement (d) is False

  • T. aquaticus is a thermophile — it requires high temperatures to grow, usually between 70°C to 80°C.
  • It was discovered in the hot springs of Yellowstone National Park (USA), not in cold regions like Antarctica.
  • Psychrophiles, not thermophiles, are adapted to survive in frozen environments.

🧬 4. Characteristics of Thermus aquaticus

Feature Description
Type Thermophilic bacterium
Optimum Growth Temperature 70°C to 80°C
Enzyme Taq polymerase
Survival Conditions High temperatures, low pH
Discovery Location Yellowstone National Park, USA

🔎 5. How Taq Polymerase Works in PCR

  1. Denaturation – DNA strands are separated by heating to 94–98°C.
  2. Annealing – Primers bind to the target sequence at 50–65°C.
  3. Extension – Taq polymerase synthesizes a new DNA strand at 72°C.

💡 6. Why Taq Polymerase is Ideal for PCR

✅ Thermostability → Functions at high temperatures.
✅ Fast replication rate → Efficient DNA amplification.
✅ High fidelity → Minimal errors during DNA synthesis.


🚀 7. Applications of Taq Polymerase

1. Genetic Research

  • DNA cloning and sequencing
  • Genotyping and mutation analysis

2. Medical Diagnosis

  • Detecting infectious diseases
  • Identifying genetic mutations

3. Forensic Science

  • DNA fingerprinting
  • Crime scene investigation

4. Evolutionary Biology

  • Studying ancient DNA
  • Phylogenetic analysis

Summary

  • T. aquaticus is a thermophilic bacterium found in hot springs.
  • Its enzyme Taq polymerase is widely used in PCR due to its heat stability.
  • It cannot survive in cold environments like Antarctica, making statement (d) false.
  • ✅ Correct Answer: (d) T. aquaticus is found in the frozen lakes of Antarctica.
6 Comments
  • Akshay mahawar
    March 17, 2025

    Done 👍

  • Ujjwal
    March 17, 2025

    Okh

  • Suman bhakar
    March 17, 2025

    💯

  • Nisha
    March 17, 2025

    Done

  • Arushi
    March 17, 2025

    👍👍

  • Parul
    March 22, 2025

    Done sir. Easy

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