Which of the following ethylene receptors in Arabidopsis) have intrinsic histidine kinase activity, and this activity does not appear to play an essential role in signalling?

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#Question id: 16121

#Unit 7. System Physiology – Animal

 Match the following mechanisms (Column I) with their correct example (Column II).

Column I	Column II
A. Heat-generating and heat-retaining mechanisms	i. increased metabolic rate (thyroid hormones, sympathetic nervous system)
B. Heat-dissipating mechanisms	ii. vasodilation of blood vessels of the skin (decreased sympathetic tone)
	iii. increased activity of sympathetic cholinergic fibers to sweat glands.
	iv. shivering
	v. vasoconstriction of blood vessels of the skin (increased sympathetic tone)

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#Question id: 16122

#Unit 7. System Physiology – Animal

Fever is an abnormal elevation of body temperature. Following statements are regarding to the cellular mechanism of fever.

A. Pyrogens produce fever by increasing the hypothalamic set-point temperature.

B. the mechanism of pyrogen action is increased production of interleukin-1 (IL-1) in phagocytic cells.

C. IL-1 then acts on the anterior hypothalamus to increase local production of prostaglandins, which increase the set-point temperature.

D. IL-1 then acts on the posterior hypothalamus to increase local production of prostaglandins, which increase the set-point temperature.

E. IL-1 then acts on the posterior hypothalamus to increase local production of prostaglandins, which decrease the set-point temperature.

Which of the following combination is correct?

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#Question id: 16123

#Unit 7. System Physiology – Animal

How fever can be reduced by aspirin?

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#Question id: 16124

#Unit 7. System Physiology – Animal

Thermoreceptors are:

a) activated only by severe cold or severe hot

b) located on the superficial layers of the skin

c) a subtype of nociceptors

d) on dendritic endings of A delta fibres and C fibres

which of following combination is correct?

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#Question id: 16125

#Unit 13. Methods in Biology

You are studying regulation of the yeast enzyme glutamine synthetase (GS), which is encoded by the GLN1 gene. You have isolated two mutants, designated gln2– and gln3–, that give decreased GS activity. Mating of either gln2– or gln3– haploids to wild type produces heterozygous diploids that show normal amounts of GS expression. When you cross either a gln2– or gln3– haploid to a gln1– strain the resulting diploids show normal expression of GS.              

From these experiments,  Classify  the  gln2– and gln3– mutations in terms of their basic genetic properties explaining the rationale behind your conclusions. Based on these properties make a proposal for the types of regulatory functions affected by the gln2– and gln3– mutations.

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#Question id: 16126

#Unit 13. Methods in Biology

2 You are studying regulation of the yeast enzyme glutamine synthetase (GS), which is encoded by the GLN1 gene. You have isolated two mutants, designated gln2– and gln3–, that give decreased GS activity. Mating of either gln2– or gln3– haploids to wild type produces heterozygous diploids that show normal amounts of GS expression. When you cross either a gln2– or gln3– haploid to a gln1– strain the resulting diploids show normal expression of GS, that could explain the effect of the gln2– and gln3– mutations on the regulation of GLN1.

The GLN1 gene shows a rather complex regulation in response to different amino acids. When either glutamate (glu) or glutamine (gln) is added to the medium, the amount of GS expression diminished and when both glutamate and glutamine are added to the medium GS expression is shut off completely. The effects of different mutants on the response to glu and gln are shown below.