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NET XL December 2015 Question Paper with Answer Key (Part II)


Life Sciences NET Dec 2015

Previous Year Question Papers of CSIR – UGC /JRF/NET: Life Science Examination, December 2015 (II)
COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH (CSIR) & UGC
(Original Question Paper with Answer Key, Explanations and References)

PART: B (Questions 41 – 60)


(41). Phenylalanine, a precursor of most of the phenolics in higher plants is a product of which one of the following pathways?

a.       Shikimic acid pathway
b.      Malonic acid pathway
c.       Mevalonic acid pathway
d.      Methylerythritol pathway

Ans. (a)

Shikimic acid pathway is a metabolic seven step pathway in bacterial, fungi, and plants for the synthesis of aromatic amino acids such as Phenylalanine, tyrosine and tryptophan. Shikimic acid pathway is completely absent in animals and hence all the above amino acids are essential amino acids to animals

Mevalonic acid pathway is for the production of  isoprenoids.

(42). For which one of the following physiological studies 12CO2 and 13CO2 are used?

a.       Estimate the rate of photosynthesis
b.      Determine rate of photorespiration
c.       The ratio of C4 and CAM pathways of CO2 fixation
d.      The ratio of C3 and C4 pathways of CO2 fixation

Ans. (d)

(43). Gibberellic acid (GA) controls seed germination by directing breakdown of the stored starch. In which one of the following tissues of the barley seed, – amylase gene is induced in response to GA?

a.       Endosperm
b.      Coleoptile
c.       Aleurone layer
d.      Embryo

Ans. (c)

During seed germination, plant embryo produces gibberellin which triggers the aleurone cells to release α-amylase for the hydrolysis of starch stored in the endosperm.

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