Biological and Medical Uses of Radiation

Biological and Medical Uses of Radiation MDCAT MCQs with answers

18 past paper MCQs on Biological and Medical Uses of Radiation, from the Nuclear Physics unit of MDCAT Physics. The year each question appeared is shown where known; tap “Show answer” for the correct option and a short solution.

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1.Which of the following is NOT a somatic biological effect of radiation? (MDCAT 2024)

  1. skin burn
  2. loss of hair
  3. induction of cancer
  4. gene mutation
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Correct answer: (d) gene mutation

A mutation of the genes is a genetic effect, carried to the offspring; the others appear in the body of the exposed person.

2.Which of the following is NOT the Somatic biological effect of radiation? (UHS MDCAT 2024)

  1. Skin burn
  2. Loss of hair
  3. Induction of cancer
  4. Genes mutation
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Correct answer: (d) Genes mutation

A somatic effect appears in the person irradiated; a mutation in the germ cells is a genetic effect.

3.Gamma ray camera can observe radiations from the ____ that are concentrated in the organs (KMU MDCAT 2024)

  1. Atoms
  2. Isotopes
  3. Nucleons
  4. Neutrons
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Correct answer: (b) Isotopes

A gamma camera images the radioisotope that has gathered in the organ under study.

4.One rem is equal to: (NUMS MDCAT 2024)

  1. 0.01 Gy / RBE
  2. 0.01 Gy × RBE
  3. 0.01 RBE
  4. 0.01 Gy
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Correct answer: (b) 0.01 Gy × RBE

The dose equivalent in rem is the absorbed dose in rad multiplied by the relative biological effectiveness.

5.1 rad is equal to: (NUMS MDCAT 2024)

  1. 0.01 J/Kg
  2. 0.01 Kg/J
  3. 0.01 J
  4. 0.01 Kg
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Correct answer: (a) 0.01 J/Kg

One rad is $0.01\,\mathrm{J}$ absorbed in each kilogram.

6.60 kg man absorbs lethal dose of 200 rem with RBE factor of 10. Energy absorbed is: (NUMS MDCAT 2024)

  1. 9J
  2. 8J
  3. 10J
  4. 12J
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Correct answer: (d) 12J

$200\,\mathrm{rem}$ with an RBE of ten is $20\,\mathrm{rad}$, that is $0.2\,\mathrm{J\,kg^{-1}}$, and $0.2\times60$ is $12\,\mathrm{J}$.

7.Somatic effect causes: (NUMS MDCAT 2024)

  1. Gene deformation
  2. Chromosomes deformation
  3. Skin burns
  4. Eye burns
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Correct answer: (c) Skin burns

A somatic effect shows in the body irradiated; damage to the genes is a genetic effect.

8.Each person experiences background radiation dose in one year: (NUMS MDCAT 2024)

  1. 1mSv
  2. 1mGy
  3. 1Gy
  4. 1Sv
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Correct answer: (a) 1mSv

Natural background gives about a millisievert a year.

9.Q.174 A low energy neutron has RBE factor of 10. How much energy is absorbed by a man of mass 80 Kg if the value of equivalent dose is 400 rem? (UHS MDCAT 2023)

  1. 16 J
  2. 32 J
  3. 48 J
  4. 64 J
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Correct answer: (b) 32 J

$400\,\mathrm{rem}$ with an RBE of ten is $40\,\mathrm{rad}$, that is $0.4\,\mathrm{J\,kg^{-1}}$, and $0.4\times80$ is $32\,\mathrm{J}$.

10.Skin burns, loss of hair, drop in the white blood cells etc. are examples of: (SZABMU MDCAT 2023)

  1. Somatic effect
  2. Genetic effect
  3. Metabolism effect
  4. Mutation effect
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Correct answer: (a) Somatic effect

These appear in the person irradiated, so they are somatic effects.

11.The SI unit of equivalent dose is: (UHS MDCAT 2023)

  1. Gray
  2. Mass
  3. Rad
  4. Sievert
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Correct answer: (d) Sievert

Equivalent dose is measured in sieverts.

12.In water pipes _________ is used to detect leakages: (PMC MDCAT 2022)

  1. Radioisotope
  2. Light
  3. Current
  4. Heat
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Correct answer: (a) Radioisotope

A tracer added to the water shows up where it escapes from the buried pipe.

13.Which radiation is used in smoke detectors? (PMC Practice 2021)

  1. Alpha
  2. Beta
  3. Gamma
  4. All of these
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Correct answer: (a) Alpha

Alpha particles ionize the air in the chamber, and smoke interrupts the tiny current.

14.Radiations are classified by its ______ nature. (PMC Practice 2021)

  1. Ionizing
  2. Non ionizing
  3. Both a and b
  4. Radiations cannot be classified
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Correct answer: (c) Both a and b

Radiation is classed as ionizing or non-ionizing by what it does to the atoms it passes.

15.While using radiation therapy, cancerous thyroid is treated with ____ radioisotope: (PMC MDCAT 2020)

  1. Carbon
  2. 235 Uranium
  3. Thorium
  4. Iodine
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Correct answer: (d) Iodine

Iodine-131 gathers in the thyroid, so it is used to treat thyroid cancer.

16.Sodium-24 is used for: (UHS MDCAT 2016)

  1. Sterilization
  2. Study of circulation of blood
  3. Skin Cancer
  4. Thyroid Cancer
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Correct answer: (b) Study of circulation of blood

Sodium-24 is injected as common salt and followed with a counter to trace the circulation.

17.Radioisotope which is used to combat cancer of thyroid gland is: (UHS MDCAT 2016)

  1. Iodine-131
  2. Phosphorous-32
  3. Strontium-90
  4. Cobalt-60
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Correct answer: (a) Iodine-131

Iodine-131 gathers in the thyroid and irradiates it from within.

18.Energy radiation absorbed at the rate of one joule per kilogram is called: (UHS MDCAT 2016)

  1. 1 Rad
  2. 1 Sievert
  3. 1 Yellow
  4. 1 Gray
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Correct answer: (d) 1 Gray

One gray is one joule absorbed in each kilogram.

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