All Free Biology MCQs with Answers

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19844 questions · page 686 of 1985

6851. Which one of the following is a congenital disease?

Moderate
  • A. Uremia
  • B. Glycogenosis
  • C. Myocardial infarction
  • D. Cerebral infarction

Explanation: It is a lysosomal disorder which is inherited by birth as a genetic deficiency.

Correct answer: Glycogenosis

6852. Which one of the following is not true about Tay sach's disease?

Moderate
  • A. Mental disorder
  • B. Congenital disorder
  • C. Lysosomal disorder
  • D. Cardiovascular disorder

Explanation: Tay sach's diseases is a congenital disorder due to deficiency of a particular lysosome (enzyme) associated with catabolism of lipids. As a result, lipids accumulate in brain and a mentaldisorder appears which may lead to death.

Correct answer: Cardiovascular disorder

6853. Tay sach's disease is due to deficiency of an enzyme associated with:

Moderate
  • A. Metabolism
  • B. Anabolism
  • C. Catabolism
  • D. Catalysis

Explanation: Glyoxisomes contain such enzymes which are associated with conversion of stored fatty acids to carbohydrates in seedlings of oil yielding plants.

Correct answer: Catabolism

6854. Following organelles are derived from special assemblies of microtubules, EXCEPT:

Moderate
  • A. Cilia
  • B. Flagella
  • C. Centrioles
  • D. Microbodies

Explanation: Microbodies are simple membrane-bounded vesicular organelles like peroxisomes and glyoxisomes.

Correct answer: Microbodies

6855. Cyclosis occurs due to the involvement of:

Moderate
  • A. Microtubules
  • B. Microfilaments
  • C. Intermediate filaments
  • D. Myofilaments

Explanation: Microfilaments are made up of contractile actin proteins. They contract and relax rhythmically in a cell and generate a pumping pressure that forces the cytoplasm to carry out a mass movementor streaming movement in a clockwise manner around the nucleus. It is called cyclosis.

Correct answer: Microfilaments

6856. Intermediate filaments are called so because they have intermediate:

Moderate
  • A. Position in cell
  • B. Composition
  • C. Length
  • D. Diameter

Explanation: Fact: The diameter of intermediate filaments is in between that of microtubules and microfilaments.

Correct answer: Diameter

6857. Absence of an enzyme that is involved in the catabolism of lipids may ultimately result in:

Moderate
  • A. Glycogenosis
  • B. Lysosomal disorder
  • C. Mental retardation
  • D. Storage disease

Explanation: Due to the deficiency of such enzymes, lipids are accumulated in the brain cells, which lead to mental retardation or even death. The disorder is called Tay Sach's disease.

Correct answer: Mental retardation

6858. The most undesirable consequence of Tay Sach's disease is:

Moderate
  • A. Accumulation of lipids in brain cells
  • B. Mental retardation
  • C. Death
  • D. Absence of an enzyme involved in catabolism of lipids

Explanation: The worst consequence of the accumulation of lipids in brain is the death of human being. Even with the best care, children with infantile Tay Sach's disease usually die at the age of 4.

Correct answer: Death

6859. Following events are associated with a lysosomal disorder called Tay Sach's disease. Arrange them in a specific sequence with respect to their occurrence: i. Mental retardation ii. Inheritance of abnormal gene iii. Accumulation of lipids in brain cells iv. Lack of catabolism of lipids v. Absence of an enzyme

Moderate
  • A. i, ii, iii, iv, v
  • B. v, iv, iii, ii, i
  • C. ii, iv, i, iii, v
  • D. ii, v, iv, iii, i

Explanation: When someone inherits an abnormal gene associated with the synthesis of the enzyme required for the catabolism of lipids, the person will lack such enzymes. As a consequence, there willbe no catabolism of lipids, and lipids will be accumulated in the brain cells. It will result in mental retardation.

Correct answer: ii, v, iv, iii, i

6860. Events associated with lysosomal disorders are mentioned below. Arrange them in a sequence with respect to their occurrence: i. Mutation ii. Storage diseases iii. Accumulation of substances within the cells iv. Deficiency of lysosomal enzymes v. Metabolic sluggishness

Moderate
  • A. i, ii, iii, iv, v
  • B. i, iv, v, iii, ii
  • C. v, iv, iii, ii, i
  • D. ii, iii, iv, v, i

Explanation: When the gene associated with enzyme synthesis is mutated, the enzyme becomes deficient, and as a result, the metabolic process becomes sluggish, and the substrate (substance) starts to accumulate in the cells. This results in storage disease.

Correct answer: i, iv, v, iii, ii