Examples of Krok 1 tests

85. In modern biochemical investigations for diagnostics of inherited diseases, detection of certain viruses (for example HIV), authentification of individual (gene dactylography in forensic medicine) so called "DNA-diagnostics" is imployed. What method is used in these investigations?

A. Polymerase chain reaction

B. Chromatography

C. Electrophoresis

D. Rentgen-structural analysis

E. Electron microscopy

86. From nitrates, nitrites and nitrosamines in organism is formed nitrous acid which causes oxidative deamination of nitrogene bases of nucleotides. This induce a point mutation by replacement of cytosine to:

A. Uracil

B. Thymine

C. Adenine

D. Guanine

E. Inosine

87. 5’-bromouracil inhibits the biosynthesis of one from the listed below compounds. Chose this compound:

1. DNA

2. Protein

3. mRNA

4. rRNA

5. Histones

88. A physician prescribed allopurinol to a patient suffering from gout. What pharmacological property of allopurinol provides a therapeutic effect in this case?

1. Competitive inhibition of xanthine oxydase

2. Acceleration of pyrimidine nucleotides catabolism.

3. Increace of nitrogen-containing substances excretion.

4. Decrease of pyrimidine nucleotides reutilization.

5. Acceleration of nucleic acids biosynthesis

89. In a child a physical and mental underdevelopment is observed. In urine is excreted large quantity of orotic acid. This hereditary disease is a result of the next metabolic disorder:

A. Pyrimidine nucleotides synthesis

B. Pyrimidine nucleotides breakdown

C. Purine nucleotides synthesis

D. Purine nucleotides breakdown

E. Ornithine cycle of urea production

90. In one month old child an enhanced content of orotic acid in urine is detected, a child has diminished weight gain. What treatment must be undertaken in order to correct metabolic disorders?

A. Injections of uridine

B. Injections of adenosine

C. Injections of guanosine

D. Injections of thymidine

E. Injections of histidine

91. The decrease of uric acid concentration and the accumulation of xanthine and hvpoxanthine were found in the blood of a 12-year-old boy. The genetic defect of the synthesis of what enzyme does it testifies to?

A. Xanthine oxydase

B. Arginase

C. Urease

D. Ornithine carbamoyl transferase

E. Glycerol kinase

92. RNA of AIDS virus invaded leukocyte and caused production of viral DNA in a cell with the aid of the enzyme revertase. This is based on the next process:

A. Reversed transcription

B. Operone activation

C. Operone repression

D. Convariant replication

E. Reversed translation

93. Into human body were incorporated mercury ions. This led to the increase in rate of transcription of the gene, responsible for detoxification of heavy metals. What protein gene amplification is in the background of this process?

A. Metallothioneine

B. Ceruloplasmin

C. Interferone

D. Transferrin

E. Ferritin

94. Oncology patient was administered an antitumor drug – metothrexate. After some period tumor cells lost sensitivity to this drug. What gene amplification caused this effect?

A. Dihydrofolate reductase

B. Glutathion reductase

C. Thioredoxine reductase

D. Ribonucleitide reductase

E. Methemoglobin reductase

95. For identification of father of a child is used the next analytical technique:

A. Polymerase chain reaction (PCR)

B. Northern blot analysis

C. Restriction fragmrnt length polymorphism analysis

D. DNA fingerprint analysis

E. Southern blot analysis

96. In oncology patients prolong application of antitumor drugs induce appearance of resistance of target cells to this drugs. What process is responsible for this effect?

A. Gene mutation

B. Gene recombination

C. Gene modification

D. Gene expression

E. Gene amplification

97. In a patient was recognized endemic goiter. What type of post-translational modification of thyroglobuline is damaged in a patient?

1. Iodination

2. Phosphorylation

3. Methylation

4. Acetylation

5. Glycosylation

98. A 50-year-old patient is diagnosed with gout and there is hyperuricemia in his blood. The metabolism of what substances is disturbed?

A. Purines

B. Fats

C. Amino acids

D. Carbohydrates

E. Pyrimidines.

99. The samples of blood of a child and of a supposed father were directed for affiliation to medical forensic examination. Which chemical components need to be identified in the explored samples of blood?

1. DNA

2. tRNA

3. rRNA

4. mRNA

5. mnRNA

100. Parents of a 5-year-old child consulted a doctor. Examination of the child discovered retardation in mental development and growth, as well as abasement of the child's agility. The basal metabolism is lowered. What disease does the child suffer from?

A. Lesch-Nyhan syndrome.

B. Cretinism.

C. Phenylketonuria.

D. Hyperparathyroidism.

E. Endemic goiter.

101. A 65-year-old man, suffering from gout, complains of pains in the area of kidneys. Ultrasonic inspection revealed the presence of stones inside the kidneys. Which biochemical process is the main cause of kidney stones formation?

A. Degradation of purine nucleotides.

B. Catabolism of proteins.

C. Ornithine cycle.

D. Degradation of heme.

E. Reduction of cysteine.

102. In a man 45 years old, suffering from gout, increased concentration of uric acid in blood was observed. For treatment allopurinol was administered, which is a competitive inhibitor of the following enzyme:

A. Xanthine oxidase

B. Adenosine deaminase

C. Hypoxanthine phosphoribosyl transferase

D. Guanine deaminase

E. Adenin phosphoribosyl transferase

103. An 8-year-old boy suffers from Lesch-Nyhan's disease. The increased concentration of uric acid was determined in his blood. Which biochemical process disorder is the cause of this inherited disease?

A. Degradation of purine nucleotides

B. Synthesis of purine nucleotides.

C. Synthesis of pyrimidine nucleotides.

D. Degradation of pyrimidine nucleotides.

E. Synthesis of deoxyribonucleotides

104. A 72 years old woman complains on pains in joints, restriction of movement in joints. The joints are swollen, looking as enlarged knots. In blood and urine an increased concentration of uric acid is detected. What disease is characterized by these symptoms?

A.Gout

B.Pellagra

C.Alkaptonuria

D.Thyrosinosis

E.Liver cirrhosis

105. If a double-stranded DNA molecule undergoes two rounds of replication in an in vitro system that contains all of the necessary enzymes and nucleoside triphosphates that have been labeled with 32P, which of the following best describes the distribution of radioactivity in the four resulting DNA molecules?

A. Two of the molecules contain radioactivity in both strands.

B. Exactly one of the molecules contains radioactivity in only one strand.

C. Exactly one of the molecules contains no radioactivity.

D. Three of the molecules contain radioactivity in both strands.

E. All four molecules contain radioactivity in only one strand.