The colored pigments of plants are of two principal types: carotenoids and flavonoids. Given below some statements of about these pigments;

 a) Anthocyanins are colored flavonoids that attract animals

b) Flavonoids are phenolic compounds that include a wide range of colored substances

c) Carotenoids are coloured terpenoid compounds that also serve as accessory pigments in photosynthesis

d) most widespread group of pigmented carotenoids is the anthocyanins, these are glycosides that have sugars. Without their sugars, anthocyanins are known as anthocyanidins

Which of the following is incorrect statements of these pigments;

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#Question id: 18956

#Unit 13. Methods in Biology

It is possible to calculate the number of clones that must be present in a gene library to give a probability of obtaining a particular DNA sequence. This formula is:

 

where N is the number of recombinants, P is the probability and f is the fraction of the genome in one insert. Thus for the E. coli DNA chromosome of 5 × 10 ⁶ bp andan insert size of 20 kb ( f = 0.004), the number of clones needed ( N ) would be 1 × 10 ³ ,with a probability of P will be

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#Question id: 18957

#Unit 13. Methods in Biology

A DNA fragment of 5000bp needs to be isolated from E.coli (genome size 4x103kb) genomic library. The minimum number of independent recombinant clones required to represent this fragment in genomic library are

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#Question id: 18958

#Unit 13. Methods in Biology

The number of clones to represent this fragment in genomic library with a probability of 95% are

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#Question id: 18959

#Unit 13. Methods in Biology

 Vectors used for construction of genomic libraries, and their capacity is given match them correctly

A- λ EMBL series	I - 300kb - 1,400 kb
B - Cosmids	II - 45 kb
C - BACs and YACs (high capacity vectors)	III - 20kb

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#Question id: 18960

#Unit 13. Methods in Biology

cDNA library do not require very large vectors hence which of the following is commonly used in cDNA library

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#Question id: 18961

#Unit 13. Methods in Biology

When a cDNA library is generated by first removing those mRNA or cDNA sequences that are common to two sources, e.g., two different Cell types, such a library is called