Genetics related MCQ

Genetics as it applies to evolution, molecular biology, and medical aspects.

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Genetics related MCQ

Post by Navin » Fri Nov 30, 2007 9:20 am

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 :)
Last edited by Navin on Fri Nov 30, 2007 7:28 pm, edited 2 times in total.
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Post by mith » Fri Nov 30, 2007 3:18 pm

1. Transformation can be only plasmid transfer
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Post by Navin » Fri Nov 30, 2007 3:32 pm

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.
Botany is the study of what? Bottoms!

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