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  • Question 1 - 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
      11.3
      Seconds

  • Question 2 - Regarding DNA cloning and sequencing, all of the following are true, except: ...

    Incorrect

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

      Your Answer: In sequencing dideoxysequencing allows identification of exact nucleotide sequence

      Correct 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
      21.1
      Seconds

  • Question 3 - In which stage of mitosis are the chromosomes most obvious or prominent? ...

    Correct

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

      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
      6.1
      Seconds

  • Question 4 - The mitochondrial chromosome is a circular DNA molecule. They encode for proteins needed...

    Incorrect

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

      Your Answer: Oxidative phosphorylation

      Correct 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
      488.5
      Seconds

  • Question 5 - 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
      8
      Seconds

  • Question 6 - 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: Interphase

      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
      11.7
      Seconds

  • Question 7 - 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
      14.9
      Seconds

  • Question 8 - The chromosomes that principally encode for proteins or RNA molecules involved in mitochondrial...

    Correct

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

      Your 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
      19
      Seconds

  • Question 9 - The process by which DNA fragments are separated by gel and transferred onto...

    Correct

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

      Your 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
      6.6
      Seconds

  • Question 10 - Which of the following is not true regarding mitochondrial chromosome disorders? ...

    Correct

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

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

      Explanation:

      Any point mutation in any part of the mitochondrial DNA will lead to a mutated mitochondria and will likewise have its ill effect on the body.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      10
      Seconds

  • Question 11 - Which of the following is not true regarding mitochondrial chromosome disorders? ...

    Correct

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

      Your 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
      7.3
      Seconds

  • Question 12 - Telomerase is active in the following cells except: ...

    Incorrect

    • Telomerase is active in the following cells except:

      Your Answer: Certain liver 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
      12.8
      Seconds

  • Question 13 - 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
      8.4
      Seconds

  • Question 14 - Mutation in RB can lead to the formation of which cancer? ...

    Incorrect

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

      Your Answer: Breast cancer

      Correct 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
      16.1
      Seconds

  • Question 15 - The process of DNA amplification and quantification is called: ...

    Incorrect

    • The process of DNA amplification and quantification is called:

      Your Answer: Southern blotting

      Correct 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
      10
      Seconds

  • Question 16 - Telomerase is active in all of the following cells, except: ...

    Incorrect

    • Telomerase is active in all of the following cells, except:

      Your Answer: Certain osteoblasts

      Correct Answer: Certain liver cells

      Explanation:

      Telomerase is an enzyme that adds repetitive nucleotide sequences to the ends of chromosomes (telomeres), preventing their shortening during cell division. Telomerase activity is crucial for cells that divide frequently and need to maintain their telomere length for continued proliferation. These include:

      • Stem cells: They have high telomerase activity to maintain their long-term proliferative capacity.
      • Germ cells: These cells also have active telomerase to ensure the stability of genetic material across generations.
      • Certain white blood cells: Some immune cells, particularly those that need to proliferate in response to infection, show telomerase activity.
      • Certain cancer cells: Many cancer cells reactivate telomerase, which contributes to their uncontrolled growth and immortality.

      However, most somatic cells, including certain liver cells, do not exhibit significant telomerase activity. While some liver cells might show low levels of telomerase activity during regeneration, it is not generally active in normal, differentiated liver cells.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      6.2
      Seconds

  • Question 17 - 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
      7.7
      Seconds

  • Question 18 - 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
      16
      Seconds

  • Question 19 - The length of DNA is generally measured in terms of number of: ...

    Incorrect

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

      Your Answer: Nucleotides

      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
      9.5
      Seconds

  • Question 20 - Consanguinity shows a strong association with which pattern of inheritance? ...

    Correct

    • Consanguinity shows a strong association with which pattern of inheritance?

      Your Answer: Autosomal recessive

      Explanation:

      Consanguinity involves being from the same kinship as another person. It is a common feature of an autosomal recessive mode of inheritance

    • This question is part of the following fields:

      • Genetics
      • Medicine
      4.6
      Seconds

  • Question 21 - Which of the following is an incorrect statement regarding the structure of DNA?...

    Correct

    • Which of the following is an incorrect statement regarding the structure of DNA?

      Your Answer: The two strands of DNA are held together by cysteine bonds.

      Explanation:

      The two strands of DNA are held together by hydrogen bonds formed between the nucleotide bases.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      14.8
      Seconds

  • Question 22 - The process whereby DNA fragments are separated by size and charge is called:...

    Correct

    • The process whereby DNA fragments are separated by size and charge is called:

      Your Answer: Gel electrophoresis

      Explanation:

      Fragments of DNA of varying length can be separated on the basis of their charge and their size by a process called gel electrophoresis. Because DNA contains negatively charged phosphate groups, it will migrate in an electric field toward the positive electrode. Shorter chains migrate more rapidly through the pores of the gel, and thus separation depends on length. DNA bands in the gel can be visualized by various techniques including staining with dyes and autoradiography.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5
      Seconds

  • Question 23 - When during the cell cycle do the centrioles replicate? ...

    Incorrect

    • When during the cell cycle do the centrioles replicate?

      Your Answer: G2 phase

      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
      7.7
      Seconds

  • Question 24 - Male to male transmission is a key factor of which type of inheritance?...

    Incorrect

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

      Your Answer: Autosomal recessive

      Correct 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
      5.8
      Seconds

  • Question 25 - 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
      9.6
      Seconds

  • Question 26 - 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
      3.3
      Seconds

  • Question 27 - Defects in chromosomal structure (and examples) include those mentioned below except: ...

    Incorrect

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

      Your Answer: Robertsonian translocation (down syndrome in subsequent generation)

      Correct 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
      13.5
      Seconds

  • Question 28 - 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
      2.1
      Seconds

  • Question 29 - Normal eukaryote somatic cells have: ...

    Correct

    • Normal eukaryote somatic cells have:

      Your Answer: 23 pairs of chromosomes

      Explanation:

      A normal somatic eukaryotic cell contains 46 chromosomes i.e. 23 pairs.

    • This question is part of the following fields:

      • Genetics
      • Medicine
      5.9
      Seconds

  • Question 30 - Regarding Southern Blotting and DNA probes, which answer is FALSE ...

    Correct

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

      Your 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
      19
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Genetics (19/30) 63%
Medicine (19/30) 63%
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