Genetics related MCQ

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    • #8684

      I managed to get my hand on my exam booklet – and here are several qns that stumped me. I’ll post the qns first, then followed by my reasoned answers.

      1. What process in bacteria ALWAYS allow both chromosomal and non-chromosomal DNA to be transferred?
      A binary fission
      B conjugation
      C transduction
      D transformation

      2.What describes common features of the telomere and the centromere?
      A both have protein associated with them
      B both are made up of DNA with a high incidence of A and T
      C both DNA are conserved throughout the life of the organism
      D During interphae, replication takes plae simultaneously in both regions

      3. Which statements are true?
      1 Continuous variation is always influenced by the environment
      2 Continuous variation is always caused by many genes
      3 Discontinuous variation is always caused by one gene
      4 Discontinuous variation is sometimes influenced by the environment
      A 1&4, B 2&3, C 2&4, D 3&4

      4. Which process cld produce a large number of genetically identical plants?
      A anther culture
      B embryo culture
      C pollen cultue
      D protoplast culture

      My attempts:
      For 1,i chose D – but now I’m unsure if A cld be the answer. Is the plasmid also transferred during binary fission?
      For 2, i chose A as there are kinetochore proteins and the enzyme telomerase. But the rest seem plausible too.
      For 3, i chose C, i know 4 is definitely true(i know some examples) and 3 definitely false – but what about 1 and 2?
      For 4, i chose D, although i completely have no clue how to tackle this qn.
      Any help would greatly be appreciated. Thanks 🙂

    • #78755

      1. Transformation can be only plasmid transfer

    • #78756

      Not really – besides plasmid transformation, there is also the uptake of naked DNA when bacteria in natural populations are in a state of natural competence. Fragments of chromosomal DNA from lysed bacteria can enter into neigbouring bacteria (then followed by homologous recombination).

      There is a famous experiment showing this: avirulent Streptococcus pneumoniae became virulent by being exposed to heat-killed virulent cells.

      But I see your point; the question stresses ALWAYS, so i guess transformation then is not the answer, as both are not always transferred.

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