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  • Question 1 - 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
      18.4
      Seconds

  • Question 2 - Telomeres are best described as: ...

    Incorrect

    • Telomeres are best described as:

      Your Answer: A complex repetitive glycoprotein structure at the end point of DNA protecting the DNA from damage.

      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
      29.8
      Seconds

  • Question 3 - The telomerase is capable of adding several more repeats of telomeres at which...

    Correct

    • The telomerase is capable of adding several more repeats of telomeres at which end of the guanosine rich region.

      Your Answer: 3rd end

      Explanation:

      Telomerase is a reverse transcriptase that uses the RNA template to synthesize DNA in the 5th-3rd direction resulting in extension of the 3rd end and then translocates it to the newly synthesized end. The GT rich strand is thus elongated.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      10.4
      Seconds

  • Question 4 - Regarding Polymerase Chain Reaction, all are true except: ...

    Correct

    • Regarding Polymerase Chain Reaction, all are true except:

      Your 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
      5.3
      Seconds

  • Question 5 - During which phase of the cell cycle does DNA synthesis occur? ...

    Correct

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

      Your 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

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.6
      Seconds

  • Question 6 - When one of the two copies of the autosomes has a mutation and...

    Correct

    • When one of the two copies of the autosomes has a mutation and the protein produced by the normal form of the gene cannot compensate. The affected individual has an:

      Your Answer: Autosomal dominant disorder

      Explanation:

      An autosomal dominant trait will be expressed no matter the consequence. If one chromosome has a mutation the other will not be able to compensate for the mutation hence the protein formed will be mutated and will not function properly.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      11.5
      Seconds

  • Question 7 - In a knockout mouse model the process used to combine the new DNA...

    Correct

    • In a knockout mouse model the process used to combine the new DNA sequence and the stem cells is known as:

      Your Answer: Insertion

      Explanation:

      Chimerisation is also known as the formation of recombinant DNA. When a foreign DNA sequence is inserted into a plasmid or other DNA sequence, this process is known as insertion.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      8.5
      Seconds

  • Question 8 - Regarding restriction fragment length polymorphisms (RFLP) and Gene Knockout Mouse Models. All are...

    Correct

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

      Your 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
      27.2
      Seconds

  • Question 9 - The following cells replicate without shortening their telomeres because they express telomerase. ...

    Correct

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

      Your 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
      12.3
      Seconds

  • Question 10 - Which of the following is true for P 53: ...

    Correct

    • Which of the following is true for P 53:

      Your 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
      4
      Seconds

  • Question 11 - 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
      6.9
      Seconds

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

    Correct

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

      Your 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
      4.1
      Seconds

  • Question 13 - Which of the following conditions results from chromosomal ‘non-disjunction’? ...

    Correct

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

      Your 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
      5.5
      Seconds

  • Question 14 - 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
      9.3
      Seconds

  • Question 15 - The process by which RNA fragments are separated by gel electrophoresis and transferred...

    Correct

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

      Your 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
      8.1
      Seconds

  • Question 16 - 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
      15.4
      Seconds

  • Question 17 - Male to male transmission is a key factor of which type of inheritance?...

    Correct

    • Male to male transmission is a key factor of which type of inheritance?

      Your Answer: Autosomal dominant

      Explanation:

      Autosomal dominant type of inheritance can include both sexes in the same ratio. There is no skipping a generation and father to son transmission is common. The passing of the trait is sex independent.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      9.6
      Seconds

  • Question 18 - Restriction Enzymes... ...

    Correct

    • Restriction Enzymes...

      Your Answer: Cut DNA sequences at specific sites

      Explanation:

      Restriction endonucleases are enzymes that recognise short sequences of double stranded DNA and cut them at specific nucleotide points or sequences. These sequences differ for different restriction endonucleases.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      8.3
      Seconds

  • Question 19 - 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
      17.9
      Seconds

  • Question 20 - Which of the following conditions is NOT X-linked recessive? ...

    Correct

    • Which of the following conditions is NOT X-linked recessive?

      Your Answer: Cystic fibrosis

      Explanation:

      Cystic fibrosis is a autosomal recessive disease with an incidence of about 1 in 2500 live births. The most common mutation occurs in the long arm of chromosome 7 which codes for the chloride channel (cystic fibrosis transmembrane conductance regulator) gene.

      To have CF, a child must inherit two abnormal genes—one from each parent. The recessive CF gene can occur in both boys and girls because it is located on non-sex-linked chromosomes called autosomal chromosomes.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.3
      Seconds

  • Question 21 - Which of the following statements is not true about mitochondrial chromosomes? ...

    Correct

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

      Your 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
      49.9
      Seconds

  • Question 22 - During which phase of meiosis does exchange of genetic material occur accounting for...

    Correct

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

      Your 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
      8.9
      Seconds

  • Question 23 - In RFLP (restriction fragment length polymorphism), the DNA fragments are separated by length...

    Correct

    • In RFLP (restriction fragment length polymorphism), the DNA fragments are separated by length through a process known as:

      Your Answer: Agarose 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
      7.9
      Seconds

  • Question 24 - Near the transcription site of a gene, the site at which RNA polymerase...

    Correct

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

      Your 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
      6.8
      Seconds

  • Question 25 - Critical shortening of Telomeres result in: ...

    Correct

    • Critical shortening of Telomeres result in:

      Your Answer: Activation of p53 and prb and cell crisis

      Explanation:

      Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect them from deterioration or from fusion with neighboring chromosomes. Each time a cell divides, its telomeres shorten. When they become critically short, they can no longer protect the chromosome ends, triggering a DNA damage response.

      This response leads to the activation of tumor suppressor proteins p53 and pRb (retinoblastoma protein). Activated p53 can induce cell cycle arrest, allowing time for DNA repair or triggering apoptosis if the damage is irreparable. Similarly, pRb helps regulate cell cycle progression and can halt the cell cycle to prevent the proliferation of cells with damaged DNA.

      As a result, the cell enters a state of crisis, characterized by widespread cell death and genomic instability, which ultimately prevents the propagation of cells with critically shortened telomeres.

      Therefore, the correct answer is:

      Activation of p53 and pRb and cell crisis

    • This question is part of the following fields:

      • Genetics
      • Medicine
      8.2
      Seconds

  • Question 26 - Which of the following statements is true regarding chromosomes? ...

    Correct

    • Which of the following statements is true regarding chromosomes?

      Your Answer: All are true

      Explanation:

      All of the above mentioned statements are true regarding chromosomes.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      26.6
      Seconds

  • Question 27 - The chromosomes that principally encode for proteins or RNA molecules involved in mitochondrial...

    Incorrect

    • The chromosomes that principally encode for proteins or RNA molecules involved in mitochondrial function are found:

      Your Answer: In the nucleolus of each diploid cell

      Correct Answer: In the nucleus of each diploid cell

      Explanation:

      While mitochondria have their own small circular DNA (mtDNA) that encodes some of the proteins and RNAs required for mitochondrial function, the majority of proteins involved in mitochondrial function are encoded by nuclear DNA. These nuclear genes are transcribed in the nucleus and then translated into proteins in the cytoplasm. The proteins are subsequently imported into the mitochondria.

      Therefore, the correct answer is:

      • In the nucleus of each diploid cell

    • This question is part of the following fields:

      • Genetics
      • Medicine
      23.7
      Seconds

  • Question 28 - 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
      15.7
      Seconds

  • Question 29 - What is the role of cyclin and cyklin-dependent kinases in mitosis: ...

    Correct

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

      Your 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
      10.6
      Seconds

  • Question 30 - In DNA cloning and sequencing, the bases in nucleotides chains are bound together...

    Correct

    • In DNA cloning and sequencing, the bases in nucleotides chains are bound together by:

      Your Answer: Hydrogen bonding.

      Explanation:

      Nucleotides will always bind together via hydrogen bonds. There are two hydrogen bonds present between thymine and adenine and three hydrogen bonds present between guanine and cytosine.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.1
      Seconds

  • Question 31 - At the end of which phase will P53 halt the cell cycle? ...

    Correct

    • At the end of which phase will P53 halt the cell cycle?

      Your Answer: G1 phase

      Explanation:

      P53 regulates the cell cycle. It regulates the progression from G1 to S phase

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.8
      Seconds

  • Question 32 - When during the cell cycle do the centrioles replicate? ...

    Correct

    • When during the cell cycle do the centrioles replicate?

      Your 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
      10.2
      Seconds

  • Question 33 - Mutation in RB can lead to the formation of which cancer? ...

    Correct

    • Mutation in RB can lead to the formation of which cancer?

      Your Answer: Retinoblastoma

      Explanation:

      Patients with a history of autosomal dominant familial retinoblastoma have at least one mutated copy of the RB gene. This predisposes the patient to develop retinoblastoma in one or both the eyes. Patients with a family history should be screened properly so that it can be detected and treated as early as possible.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      3.6
      Seconds

  • Question 34 - When 2 nucleotide chains of DNA bind together, thymine is bound to: ...

    Correct

    • When 2 nucleotide chains of DNA bind together, thymine is bound to:

      Your Answer: Adenine

      Explanation:

      As a general rule in the structure of DNA, thymine always binds to adenine with two hydrogen bonds, cytosine always binds to guanine with three hydrogen bonds and vice versa. However In the structure of RNA the only difference is that adenine binds to uracil instead of thymine. But thymine will always bind to adenine.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      3.9
      Seconds

  • Question 35 - Under normal conditions (where n represents the number of chromosome pairs), just before...

    Correct

    • Under normal conditions (where n represents the number of chromosome pairs), just before mitosis begins, how many chromosomes are contained in the nucleus of each somatic cell:

      Your Answer: 4n

      Explanation:

      In a normal somatic cell there are 2n chromosome but in a replicating cell just before mitosis the chromosomes duplicate but are still joined via the centrosome. Thus there are 4n chromosomes. After completion of mitosis the number goes back to 2n.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      2.7
      Seconds

  • Question 36 - Three adjacent nucleotides code for a particular amino acid. These are called codons....

    Correct

    • Three adjacent nucleotides code for a particular amino acid. These are called codons. How many common amino acids are there and how many potential codon combinations make up the genetic code?

      Your Answer: 20 amino acids, 64 codon combinations

      Explanation:

      There are around 20 amino acids and 61 out of the 64 combinations of codon code for these 20 common amino acids.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      6.5
      Seconds

  • Question 37 - Immortality can result from over expression of which enzyme? ...

    Correct

    • Immortality can result from over expression of which enzyme?

      Your 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
      1.9
      Seconds

  • Question 38 - In most somatic cells telomeres progressively shorten as: ...

    Correct

    • In most somatic cells telomeres progressively shorten as:

      Your 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
      4.9
      Seconds

  • Question 39 - Which of the following is false with regard to the following statement: Proto-...

    Correct

    • Which of the following is false with regard to the following statement: Proto- oncogenes can be transformed to oncogenes in the following ways.

      Your Answer: Inhibition of P53

      Explanation:

      Proto oncogenes cannot be transformed into oncogenes due to inhibition of P53 gene. There has to be a mutation in the proto oncogene. All the other options are true.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      9.7
      Seconds

  • Question 40 - Southern Blotting and DNA probes: ...

    Correct

    • Southern Blotting and DNA probes:

      Your Answer: DNA fragments are separated by gel electrophoresis and transferred onto membrane sheets in 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
      4.3
      Seconds

  • Question 41 - The process of DNA amplification and quantification is called: ...

    Correct

    • The process of DNA amplification and quantification is called:

      Your Answer: PCR

      Explanation:

      PCR/polymerase chain reaction is a procedure carried out in a test tube that can be used on the smallest amount of DNA to amplify it, allowing for millions of copies of specific nucleotides to be made.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      1.9
      Seconds

  • Question 42 - 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
      4.7
      Seconds

  • Question 43 - In Restriction Fragment Length Polymorphism (RFLP), the DNA fragments are separated by length through...

    Correct

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

      Your 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
      6.7
      Seconds

  • Question 44 - 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
      21.4
      Seconds

  • Question 45 - Which part of the chromosome plays a role in preserving its integrity and...

    Correct

    • Which part of the chromosome plays a role in preserving its integrity and stability?

      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
      5.5
      Seconds

  • Question 46 - Telomerase is active in the following cells except: ...

    Incorrect

    • Telomerase is active in the following cells except:

      Your Answer: Germ 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
      12.6
      Seconds

  • Question 47 - Which of the following is true for P53: ...

    Correct

    • Which of the following is true for P53:

      Your 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
      12.5
      Seconds

  • Question 48 - The length of DNA is generally measured in terms of the number of:...

    Correct

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

      Your 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
      6.5
      Seconds

  • Question 49 - The enzyme responsible for Telomeres to maintain their length after cell division is...

    Correct

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

      Your 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
      51.8
      Seconds

  • Question 50 - During which phase are the 2 chromatids pulled apart at the centromere? ...

    Correct

    • During which phase are the 2 chromatids pulled apart at the centromere?

      Your Answer: Anaphase

      Explanation:

      During the prometaphase the microtubule organizing centre completely develops. The spindle fibers attach to the chromosome and the centriole. It is in the Anaphase however that the spindle fibers contract pulling the sister chromatids apart. Later in the anaphase a cleave furrow beings to forms.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      4.3
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Genetics (47/50) 94%
Medicine (47/50) 94%
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