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  • Question 1 - 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
      28.1
      Seconds

  • Question 2 - What is the protective hexametric sequence at the ends of chromosomes called? ...

    Correct

    • What is the protective hexametric sequence at the ends of chromosomes called?

      Your Answer: Telomere

      Explanation:

      Telomeres are non coding DNA 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
      6.3
      Seconds

  • Question 3 - Regarding restriction fragment length polymorphisms (RFLP) and Gene Knockout Mouse Models. All are...

    Incorrect

    • Regarding restriction fragment length polymorphisms (RFLP) and Gene Knockout Mouse Models. All are true except:

      Your Answer: RFLP analysis is slow and cumbersome and is now largely obsolete

      Correct Answer: In knockout mouse models a gene is turned on through targeted mutation

      Explanation:

      In RFLP, polymorphism occurs in 98% of the non coding genome, resulting in no phenotypical change in the organism. A gene is not turned on by a mutation, rather the mutation at the restriction site will alter the DNA and the DNA will now form fragments of different lengths. PCR is a better technique than RFLP.

      A knockout, as related to genomics, refers to the use of genetic engineering to inactivate or remove one or more specific genes from an organism. Scientists create knockout organisms to study the impact of removing a gene from an organism, which often allows them to then learn something about that gene’s function.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      40.6
      Seconds

  • Question 4 - In which stage of mitosis are the chromosomes most obvious or prominent? ...

    Incorrect

    • In which stage of mitosis are the chromosomes most obvious or prominent?

      Your Answer: Prophase

      Correct 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
      6.9
      Seconds

  • Question 5 - Which statement is incorrect? ...

    Incorrect

    • Which statement is incorrect?

      Your Answer: The addition of an inverted guanine residue at the 5’ site as well as polyadenylation at the 3’ site prevents nucleases from degrading primary mRNA in the nucleus of the cell.

      Correct Answer: Translation begins when the triplet (UGA) encoding for methionine is encountered.

      Explanation:

      Translation being when the codon for methionine is encountered which is AUG not UGA. This process is known as initiation. All the other options are correct.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      35.7
      Seconds

  • Question 6 - Defects in chromosomal structure (and examples) include those mentioned below except: ...

    Correct

    • Defects in chromosomal structure (and examples) include those mentioned below except:

      Your Answer: Lyonization (x-linked disorders)

      Explanation:

      All are true except for A) Lyonization which is the inactivation of the X chromosomes in a female. It is not a chromosomal abnormality.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      16.7
      Seconds

  • Question 7 - Telomerase is active in the following cells except: ...

    Incorrect

    • Telomerase is active in the following cells except:

      Your Answer: Certain cancer cells

      Correct Answer: Certain osteoblasts

      Explanation:

      Some cells have the ability to reverse telomere shortening by expressing telomerase, an enzyme that extends the telomeres of chromosomes. Telomerase is an RNA-dependent DNA polymerase, meaning an enzyme that can make DNA using RNA as a template.

      Telomerase is not usually active in most somatic cells (cells of the body), but it’s active in germ cells (the cells that make sperm and eggs) and some adult stem cells. These are cell types that need to undergo many divisions, or, in the case of germ cells, give rise to a new organism with its telomeric “clock” reset.
      Interestingly, many cancer cells have shortened telomeres, and telomerase is active in these cells. If telomerase could be inhibited by drugs as part of cancer therapy, their excess division (and thus, the growth of the cancerous tumor) could potentially be stopped.
       A subset of liver cells with high levels of telomerase renews the organ during normal cell turnover and after injury.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      14.3
      Seconds

  • Question 8 - What is the role of cyclin and cyklin-dependent kinases in mitosis: ...

    Incorrect

    • What is the role of cyclin and cyklin-dependent kinases in mitosis:

      Your Answer: Causes splitting of the centromere

      Correct Answer: Phosphorylation of proteins that make up pre-replication complexes

      Explanation:

      There are certain regulators of the cell cycles that mediate progression through the cell cycle. These are cyclins and cyklin-dependent kinases (CDKs). They form a complex that phosphorylates protein involved in the cell cycle.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      22.7
      Seconds

  • Question 9 - The mitochondrial chromosome is a circular DNA molecule. They encode for proteins needed...

    Correct

    • The mitochondrial chromosome is a circular DNA molecule. They encode for proteins needed for ATP production. These proteins are also essential for:

      Your Answer: Apoptotic cell death

      Explanation:

      The intrinsic pathway or the mitochondrial pathway of apoptosis is activated due to the loss of BCL-2 and other antiapoptotic proteins. This loss results in the increased membrane permeability and release of cytochrome C which activates caspases downstream resulting in apoptosis.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      40.7
      Seconds

  • Question 10 - Which of the following are true when it comes to tumour suppressor genes:...

    Correct

    • Which of the following are true when it comes to tumour suppressor genes:

      Your Answer: All of the options are true

      Explanation:

      All of the above mentioned statements are true regarding tumour suppressor genes. Tumour suppressor genes generally follow the two-hit hypothesis, which implies that both alleles that code for a particular protein must be affected before an effect is manifested.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      40.7
      Seconds

  • Question 11 - Which of the following conditions results from chromosomal ‘non-disjunction’? ...

    Incorrect

    • Which of the following conditions results from chromosomal ‘non-disjunction’?

      Your Answer: Edward syndrome

      Correct Answer: All of the options

      Explanation:

      Non-disjunction can result in aneuploidy i.e. abnormal number of chromosomes in a cell. It results due to uneven division of chromosomes in the meiosis 1 or 2 phase. All the above mentioned examples are of non-disjunction.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      26.7
      Seconds

  • Question 12 - Regarding Southern Blotting and DNA probes, which answer is FALSE ...

    Incorrect

    • Regarding Southern Blotting and DNA probes, which answer is FALSE

      Your Answer: Localisation of native nucleic acid sequences within cells is part of insitu hybridisation

      Correct Answer: RNA fragments are separated by gel electrophoresis and transferred onto membrane sheets in southern blotting

      Explanation:

      Restriction enzymes always cut at different positions. There are different restriction endonucleases for different nucleotide sequences.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      16
      Seconds

  • Question 13 - The following cells replicate without shortening their telomeres because they express telomerase. ...

    Incorrect

    • The following cells replicate without shortening their telomeres because they express telomerase.

      Your Answer: Stem cells

      Correct Answer: Germ cells

      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. During replication telomeres may be lost resulting in cell death.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      70.8
      Seconds

  • Question 14 - The process by which RNA fragments are separated by gel electrophoresis and transferred...

    Incorrect

    • The process by which RNA fragments are separated by gel electrophoresis and transferred onto a membrane sheet is called:

      Your Answer: Southern blotting

      Correct Answer: Northern blotting

      Explanation:

      Blots of the gel can be made from using nitrocellulose paper. Northern blots are produced when a fragment of radioactive DNA hybridize with RNA on a nitrocellulose blot of a gel and southern blots are produced when DNA hybrize with DNA on a nitrocellulose blot of the gel.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      19.1
      Seconds

  • Question 15 - Which statement is correct? ...

    Correct

    • Which statement is correct?

      Your Answer: MtDNA principally encodes for proteins that are involved in oxidative phosphorylation for the production of ATP in the cell.

      Explanation:

      Mitochondria have no nucleus instead they contain their own free floating circular genome (MtDNA), which encodes 13 different subunits of proteins involved in oxidative phosphorylation. The remainder of the mitochondrial proteins are nuclear encoded, synthesized in the cytoplasm, and transported into the mitochondria.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      20.9
      Seconds

  • Question 16 - Which of the following with regard to DNA mutations does not fit: ...

    Incorrect

    • Which of the following with regard to DNA mutations does not fit:

      Your Answer: Point mutations are the simplest type of change and may or may not cause a clinical disorder

      Correct Answer: All gene mutations cause clinical disease entities

      Explanation:

      All gene mutations do not cause a clinical manifestation of the disease, some gene mutations are silent mutations. They are present but do not cause any disease.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      63.3
      Seconds

  • Question 17 - Which of the following is true for P53: ...

    Incorrect

    • Which of the following is true for P53:

      Your Answer: It is induced by histone deacetylase protein

      Correct Answer: It is induced by ‘broken’ DNA

      Explanation:

      P53 gene is activated as a result of damaged DNA and if that cannot be repaired then it activates apoptosis.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      37.3
      Seconds

  • Question 18 - Immortality can result from over expression of which enzyme? ...

    Incorrect

    • Immortality can result from over expression of which enzyme?

      Your Answer: Polymerase

      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
      26.5
      Seconds

  • Question 19 - What is the structure of nucleosomes? ...

    Incorrect

    • What is the structure of nucleosomes?

      Your Answer: Strands of double strand DNA + introns + exons

      Correct Answer: Strands of double strand DNA + histones

      Explanation:

      DNA is packed and condensed by binding to histone proteins. The double stranded DNA forms a complex with histone proteins which is called a nucleosome. There are 8 histone proteins contained in one core of nucleosome.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      22
      Seconds

  • Question 20 - 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: Mitosis

      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
      23.3
      Seconds

  • Question 21 - In meiosis, the period of prophase 1 involves: ...

    Incorrect

    • In meiosis, the period of prophase 1 involves:

      Your Answer: The production of two identical daughter cells

      Correct Answer: Replicated DNA condensing to form visible chromosomes

      Explanation:

      Prophase 1 has been divided into five different stages (laptotene, zygotene, pachytene, diplotene and diakinesis). In prophase 1, chromosomes are going to condense to become visible, each chromosome will contain two chromatids that are joined at the centromere.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      12.4
      Seconds

  • Question 22 - The process by which DNA fragments are separated by gel and transferred onto...

    Incorrect

    • The process by which DNA fragments are separated by gel and transferred onto a membrane sheet is called:

      Your Answer: Western blotting

      Correct Answer: Southern blotting

      Explanation:

      A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. The other forms of blotting involve the use of RNA and proteins.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      24.7
      Seconds

  • Question 23 - During which phase of meiosis does exchange of genetic material occur accounting for...

    Incorrect

    • During which phase of meiosis does exchange of genetic material occur accounting for genetic diversity between individuals:

      Your Answer:

      Correct Answer: Prophase 1

      Explanation:

      Prophase 1 has been divided into five different stages ( laptotene, zygotene, pachytene, diplotene ans diakinesis). In prophase 1 chromosomes are going to condense to become visible, each chromosome will contain two chromatids that are joined at the centromere. the nucleolus and nuclear envelope are going to disintegrate. the homologous chromosomes will form tetrad and crossing over will occur between the chromosomes (random exchange of genes), the point of exchange is known as the chiasmata, this increases genetic diversity.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      0
      Seconds

  • Question 24 - Which statement is incorrect regarding transcription of DNA? ...

    Incorrect

    • Which statement is incorrect regarding transcription of DNA?

      Your Answer:

      Correct Answer: A gene is always read in the 3’-5’ orientation and at 3’ promoter sites.

      Explanation:

      In both prokaryotes and eukaryotes RNA polymerase acts in the 5′-3′ direction and hence the RNA is transcribed in this direction. The mRNA produced is immature as it has introns as well as exons presents. It undergoes a process known as splicing to remove the exons and then interacts with the ribosomes to form proteins.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      0
      Seconds

  • Question 25 - Regarding Polymerase Chain Reaction, all are true except: ...

    Incorrect

    • Regarding Polymerase Chain Reaction, all are true except:

      Your Answer:

      Correct Answer: There is a linear rise of DNA copies during amplification.

      Explanation:

      All are true except there is a linear rise of DNA copies during amplification. There is an exponential rise in amplification of DNA.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      0
      Seconds

  • Question 26 - In which phase do chromosomes in the nucleus become completely condensed into well-defined...

    Incorrect

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

      Your Answer:

      Correct 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
      0
      Seconds

  • Question 27 - In most somatic cells telomeres progressively shorten as: ...

    Incorrect

    • In most somatic cells telomeres progressively shorten as:

      Your Answer:

      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
      0
      Seconds

  • Question 28 - When during the cell cycle do the centrioles replicate? ...

    Incorrect

    • When during the cell cycle do the centrioles replicate?

      Your Answer:

      Correct Answer: G1 phase

      Explanation:

      During G1 phase the cell will prepare for cell division. All the organelles will start to duplicate in this phase and the cell will begin to grow whilst proteins are also synthesized.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      0
      Seconds

  • Question 29 - During which stage does the mitotic apparatus dissolute? ...

    Incorrect

    • During which stage does the mitotic apparatus dissolute?

      Your Answer:

      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
      0
      Seconds

  • Question 30 - In which phase do chromosomes in the nucleus become condensed into well-defined chromosomes?...

    Incorrect

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

      Your Answer:

      Correct 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
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Genetics (8/22) 36%
Medicine (8/22) 36%
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