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  • Question 1 - Which of the following statements is not true about mitochondrial chromosomes? ...

    Incorrect

    • Which of the following statements is not true about mitochondrial chromosomes?

      Your Answer: Encode proteins that are critical to the process of apoptosis

      Correct Answer: Mitochondrial chromosomes play no role in the transmission of disease from generation to generation.

      Explanation:

      All the above mentioned statements are true except that mitochondrial DNA is passed from the mother to the child. If the child inherits the defective mitochondrial gene it will manifest some form of the disease. Commonly inherited diseases related to mitochondrial abnormality are Leber hereditary optic neuropathy and myoclonic epilepsy with ragged red fibers (MERRF).

    • This question is part of the following fields:

      • Genetics
      • Medicine
      14.6
      Seconds

  • Question 2 - During which phase of the cell cycle does transcription of DNA synthesis molecules...

    Incorrect

    • During which phase of the cell cycle does transcription of DNA synthesis molecules occur?

      Your Answer: G1

      Correct Answer: S

      Explanation:

      DNA synthesis occurs in the S phase of the cell cycle. In the G1 phase the cell prepares to divide. In G2 the cellular organelles divide and in the M phase mitosis occur. In the G0 phase the cell becomes quiescent and does not divide further.

      Interphase is composed of G1 phase (cell growth), followed by S phase (DNA synthesis), followed by G2 phase (cell growth). At the end of interphase comes the mitotic phase, which is made up of mitosis and cytokinesis and leads to the formation of two daughter cells.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      14.3
      Seconds

  • Question 3 - Normal parents have a child with a recessive condition, Tay Sachs. The chance...

    Correct

    • Normal parents have a child with a recessive condition, Tay Sachs. The chance of them having a normal child is?

      Your Answer: 75%

      Explanation:

      The chance for normal parents having a child with a recessive disease is 1:4 or 25%. As both the parents are heterozygous for this condition. They have a 3:4 chance of having a normal child or 75%.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      24.9
      Seconds

  • Question 4 - In Restriction Fragment Length Polymorphism (RFLP), the DNA fragments are separated by length through...

    Incorrect

    • In Restriction Fragment Length Polymorphism (RFLP), the DNA fragments are separated by length through a process known as:

      Your Answer: Translocation

      Correct Answer: Gel electrophoresis

      Explanation:

      Samples of DNA from individuals are broken into pieces by restriction enzymes and the fragments are separated according to their lengths via gel electrophoresis. Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first DNA profiling technique inexpensive enough to see widespread application.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      17.3
      Seconds

  • Question 5 - Which of the following is not true regarding mitochondrial chromosome disorders? ...

    Incorrect

    • Which of the following is not true regarding mitochondrial chromosome disorders?

      Your Answer: Most mitochondrial diseases are myopathies and neuropathies with a maternal pattern of inheritance.

      Correct Answer: Because mitochondrial chromosomes have no introns in their genes, any point mutation has a low likelihood of having an effect.

      Explanation:

      Mitochondrial DNA (mtDNA) does indeed lack introns, meaning that its genes are closely packed with coding sequences. This actually means that any point mutation in the mtDNA is more likely to have an effect, not less. The lack of introns means there are fewer non-coding regions where mutations can occur without affecting gene function. Thus, mutations in mtDNA often have significant consequences because they are more likely to alter essential coding sequences.

      The other statements are true:

      • Most mitochondrial diseases are myopathies and neuropathies with a maternal pattern of inheritance: This is correct because mtDNA is inherited maternally, and many mitochondrial disorders affect muscle and nerve function.
      • Retinal degeneration, diabetes mellitus, and some forms of hearing loss are some of the other diseases attributed to mitochondrial chromosome defects: These are indeed conditions associated with mitochondrial defects.
      • Mitochondrial chromosome defects are inherited from one’s mother: This is correct, as mtDNA is passed from mother to offspring.
      • Leber’s hereditary optic neuropathy (LHON), the commonest cause of blindness in young men, is an example of a mitochondrial chromosome defect: This is true; LHON is a well-known mitochondrial disorder.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      25.8
      Seconds

  • Question 6 - Which of the following is true for P 53: ...

    Incorrect

    • Which of the following is true for P 53:

      Your Answer: Induction will induce necrosis in cancerous cells

      Correct Answer: It is induced by ‘broken’ DNA

      Explanation:

      All of the above mentioned statements are true regarding tumour suppressor genes.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      15.3
      Seconds

  • Question 7 - Near the transcription site of a gene, the site at which RNA polymerase...

    Incorrect

    • Near the transcription site of a gene, the site at which RNA polymerase and its cofactors bind is known as the:

      Your Answer: Regulator

      Correct Answer: Promotor

      Explanation:

      Transcription will begin when the RNA polymerase II binds to the promotor. The promotor is a sequence of 25 nucleotides found upstream from the start site of transcription. This promotor sequence is known as the TATA box. Transcription factors also bond along with RNA polymerase to this site to form a complex. However some may bind to regulatory elements proximal to the promotor site.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      16.9
      Seconds

  • Question 8 - During which stage does the mitotic apparatus dissolute? ...

    Incorrect

    • During which stage does the mitotic apparatus dissolute?

      Your Answer: Anaphase

      Correct Answer: Telophase

      Explanation:

      In telophase the nuclear envelope along with the nucleolus will reappear. The daughter nuclei will enlarge as the chromosome will decondense again. Along with this, cytokinesis will occur. At the end of cytokinesis the daughter centrioles will move from the poles to the intercellular bridge where they will be disassembled and complete the separation of the daughter cells

    • This question is part of the following fields:

      • Genetics
      • Medicine
      9.7
      Seconds

  • Question 9 - With regard to X linked disorders which of the following are true ...

    Incorrect

    • With regard to X linked disorders which of the following are true

      Your Answer: None of the above

      Correct Answer: X linked recessive disorders usually present in males and only very rarely present in homozygous females

      Explanation:

      All are true for autosomal recessive disorders. Dominance rules for sex-linked gene loci are determined by their behaviour in the female: because the male has only one allele (except in the case of certain types of Y chromosome aneuploidy), that allele is always expressed regardless of whether it is dominant or recessive.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      20.4
      Seconds

  • Question 10 - When during the cell cycle does DNA replication occur? ...

    Incorrect

    • When during the cell cycle does DNA replication occur?

      Your Answer: Mitosis

      Correct Answer: S phase

      Explanation:

      The S phase is known as the synthesis phase. During this phase DNA will begin to replicated, as well as the synthesis of the centrosomes and associated proteins.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      11.5
      Seconds

  • Question 11 - Which of the following statements is true about chromosomes? ...

    Incorrect

    • Which of the following statements is true about chromosomes?

      Your Answer: Diploid human cells have 46 chromosomes, 23 inherited from each parent

      Correct Answer: All of the above

      Explanation:

      All of the above mentioned statements are true regarding chromosomes.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      9.7
      Seconds

  • Question 12 - The length of DNA is generally measured in terms of the number of:...

    Incorrect

    • The length of DNA is generally measured in terms of the number of:

      Your Answer: Amino acids

      Correct Answer: Base pairs

      Explanation:

      As DNA is made up of nucleotides, its length is measured by the number of base pairs in the DNA molecules.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.6
      Seconds

  • Question 13 - The enzyme responsible for Telomeres to maintain their length after cell division is...

    Incorrect

    • The enzyme responsible for Telomeres to maintain their length after cell division is called:

      Your Answer: Telomere transcriptase

      Correct Answer: Telomerase reverse transcriptase

      Explanation:

      Telomeres are non-coding DNA consisting of repetitive nucleotide sequences plus proteins that are found at the end of the linear chromosomes. They maintain the integrity of the chromosomes and prevent their shortening.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      19
      Seconds

  • Question 14 - Telomeres are best described as: ...

    Incorrect

    • Telomeres are best described as:

      Your Answer: None of the above.

      Correct Answer: A repetitive DNA sequence at the end of a DNA molecule.

      Explanation:

      Telomeres are non-coding DNA consisting of repetitive nucleotide sequences plus proteins that are found at the end of the linear chromosomes. They maintain the integrity of the chromosomes and prevent their shortening.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.8
      Seconds

  • Question 15 - In which phase do chromosomes in the nucleus become completely condensed into well-defined...

    Correct

    • In which phase do chromosomes in the nucleus become completely condensed into well-defined chromosomes?

      Your Answer: Metaphase

      Explanation:

      Prophase begins when the nucleus envelope disintegrates and the chromosomes start to condense. The chromosomes consist of two sister chromatids that are joined at a constriction known as centromere. When the cell reaches the metaphase the chromosomes are completely condensed and ready to align on the equatorial plate

    • This question is part of the following fields:

      • Genetics
      • Medicine
      6.6
      Seconds

  • Question 16 - In most somatic cells telomeres progressively shorten as: ...

    Incorrect

    • In most somatic cells telomeres progressively shorten as:

      Your Answer: None of the above

      Correct Answer: The cell divides

      Explanation:

      Telomerase activity is seen in germ cells and is absent in somatic cells. A somatic cell is any biological cell forming the body of an organism, other than a gamete, germ cell, gametocyte or undifferentiated stem cell. i.e. liver cells. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely. During replication telomeres may be lost resulting in cell death.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      10.8
      Seconds

  • Question 17 - Which of the following with regard to autosomal dominant disorders are true: ...

    Correct

    • Which of the following with regard to autosomal dominant disorders are true:

      Your Answer: The offspring of a heterozygous individual has a 50% chance of inheriting the chromosome carrying the disease allele

      Explanation:

      50% of the children will be effected from parents who are heterozygous for an autosomal dominant disorder. An allele can be dominant or recessive. Individuals, meanwhile, can be homozygous or heterozygous: individuals who are homozygous for a certain gene carry two copies of the same allele. individuals who are heterozygous for a certain gene carry two different alleles.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      30.6
      Seconds

  • Question 18 - In which phase do chromosomes in the nucleus become condensed into well-defined chromosomes?...

    Correct

    • In which phase do chromosomes in the nucleus become condensed into well-defined chromosomes?

      Your Answer: Metaphase

      Explanation:

      Prophase begins when the nucleus envelope disintegrates and the chromosomes start to condense. The chromosomes consist of two sister chromatids that are joined at a constriction known as centromere. When the cell reaches the metaphase the chromosomes are completely condensed and ready to align on the equatorial plate

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.3
      Seconds

  • Question 19 - Immortality can result from over expression of which enzyme? ...

    Incorrect

    • Immortality can result from over expression of which enzyme?

      Your Answer: None of the above

      Correct Answer: Telomerase

      Explanation:

      Telomerase activity is seen in germ cells and is absent in somatic cells. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.2
      Seconds

  • Question 20 - Regarding DNA cloning and sequencing, all of the following are true, except: ...

    Correct

    • Regarding DNA cloning and sequencing, all of the following are true, except:

      Your Answer: Yeast artificial chromosomes ( yacs) are vectors

      Explanation:

      Yeast chromosomes cannot be used as a vector. All the rest are true. Vectors can be bacteria, viruses and plasmids. DNA ligase binds the DNA fragment to the host DNA after insertion. Fluorescence can be used to visualize them.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      8
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Genetics (5/20) 25%
Medicine (5/20) 25%
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