Paclobutrazol and other inhibitors of P450 monooxygenases specifically inhibit the stage of gibberellin biosynthesis

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#Question id: 12704

#XL - R Botany

Cytoplasmic male sterility (CMS) in plants is caused by mutation in the mitochondrial genome. CMS can be restored by a nuclear gene, restorer of fertility (Rf), which is a dominant character. 

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#Question id: 12705

#XL - R Botany

In Neurospora crasssa, the mutant exhibit poky phenotype, when a female of  poky strain is crossed with a normal strain acting as a male , all progeny individuals shows poky phenotype . however, the reciprocal cross resulted in all normal progeny. These results can be explained on the basis of 

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#Question id: 12718

#XL - R Botany

primary disruptions could be signaling the plant that a change in environmental conditions has occurred and that it’s time to respond by altering existing pathways or by activating stress-response pathways. At least five different types of stress-sensing mechanisms can be distinguished:

COLUMN I	COLUMN II
A) Physical sensing	i) usually results from the detection of by-products that accumulate in cells due to the uncoupling of enzymatic or electron transfer reactions, such as the accumulation of ROS during stress caused by too much light.
B) Biophysical sensing	ii) often involves the presence of specialized proteins that have evolved to sense a particular stress; for example, calcium channels that can sense changes in temperature and alter Ca2+ homeostasis.
C) Metabolic sensing	iii) refers to modifications of DNA or RNA structure that do not alter genetic sequences, such as the changes in chromatin that occur during temperature stress.
D) Biochemical sensing	iv) refers to the mechanical effects of stress on the plant or cell structure, for example, the contraction of the plasma membrane from the cell wall during drought stress.
E) Epigenetic sensing	v) might involve changes in protein structure or enzymatic activity, such as the inhibition of different enzymes during heat stress.

 

  

Match the correct sequence sensing mechanism during in stress;

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#Question id: 12719

#XL - R Botany

Which of the following is a key enzyme in the proline biosynthetic pathway?

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#Question id: 12722

#XL - R Botany

Eleven amino-acid consensus sequence motif TAQAAKEKAXE is repeated in the protein,  is the structural characteristics of which type of group of LEA protein?

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#Question id: 12725

#XL - S Microbiology

Match the following

DNA form	Helix Direction	Number of bases per helix turn
1. B	a. Left Handed	i. 10
2.  A	b. Right Handed	ii. 12
3.  C	c. Left Handed	iii. 14
4. Z	d. Right Handed	iv. 9