MCQ Detailed View

Radiations such as alpha, beta, and gamma rays affect human tissues differently depending on their penetration ability and ionizing power. The type of radiation that causes the maximum biological damage is the gamma ray.

Gamma rays are a form of high-energy electromagnetic radiation emitted from the nucleus of radioactive atoms. Unlike alpha and beta particles, gamma rays are massless and chargeless, which allows them to travel great distances and penetrate deep into human tissues. Their penetration power is so strong that they can pass through the entire human body and even thick barriers like concrete or lead (unless very thick).

Because of this ability to penetrate deeply, gamma rays can reach and damage internal organs, tissues, and DNA. Their high frequency and short wavelength make them extremely energetic. When gamma rays interact with living cells, they ionize molecules inside the cell, leading to:

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  Breakage of DNA strands

  
  


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  Cell mutation or cell death

  
  


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  Increased cancer risk

  
  


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  Damage to bone marrow, immune system, and internal organs

  
  

On the other hand:

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  Alpha rays have very strong ionizing power but extremely low penetration. They are dangerous only if inhaled or ingested, not externally.

  
  


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  Beta rays penetrate more than alpha particles but less than gamma rays, causing moderate biological damage.

  
  


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  Microwaves are non-ionizing radiation; they mainly cause heating effects and are far less biologically damaging compared to ionizing radiation.

  
  

Thus, because of their deep penetration and ability to damage internal organs, gamma rays are considered the most biologically harmful form of radiation in terms of exposure risk. This is why gamma radiation is carefully controlled in nuclear reactors, medical imaging, and cancer radiotherapy.