11.

Phosphorylation of eIF2 a subunits (at Ser 5I) leads to 

• inactivation of Met-tRNA, binding activity of eIF2B.

• sequestration of eIF2B because of tight binding between eIF2 and eIF2B

•  degradation of eIF2B. 

• enhanced guanine exchange activity of eIF2B.

If a disease caused by an intracellular pathogen is associated with host anti-inflammatory response, which one of the following may lead to an effective therapeutic approach? 

• Treatment with TGF-b

• Treatment with macrophage activating agent

• Depletion of IFN-g from the system

• Treatment with IL-4 and IL-10 

Cervical cancer-causing papilloma virus produces two oncoproteins E6 and E7 which are responsible for interfering with cell cycle regulation by 

•  inactivating pRb and p53, respectively 

• modulating p53 and pRb, respectively

• binding to cyclin D1 and CDK4 

• activating expression of p21 

Which one of the following permits the rapid diffusion of small, water-soluble molecules between the cytoplasm of adjacent cells? 

• Tight junctions 

• Anchoring junctions 

• Adherens junctions 

• Gap junctions

Which one of the following is not true for alternative pathway of complement activation? 

• Alternative pathway uses the same membrane-attack complex as the classical pathway 

• Alternative pathway does not require antigen-antibody interactions. 

• Alternative pathway produces C3 by the same route as the classical pathway

• Certain microbial surfaces have physicochemical properties that may result in activation of alternative pathway

Fertilization in sea urchin eggs involves Ca²⁺ release from the endoplasmic reticulum for cortical granule reactivation. The major molecule responsible for releasing Ca²⁺ from intracellular stores is 

• zona pellucida glycoproteins

• protamines 

• inositol 1, 4, 5-trisphosphate

• N-acetylglucosaminidase 

What is observed phenotype when the ultrabithorax gene is deleted in Drosophila?

• The third thoracic segment is transformed into another second thoracic segment resulting in a fly with four wings. 

• Since it specifies the second thoracic segment, instead of antenna leg grows out of the head socket. 

• Since it specifies the third thoracic segment, a fly with two pairs of halters develop. 

• Since this gene fails to be expressed in the second thoracic segment, the antennae sprout in the leg position. 

Which one of the following statements with respect to amphibian development is correct?

• The organizer is itself induced by the Nieuwkoop Centre located in the dorsalmost mesodermal cells.

• The organizer functions by secreting proteins like Noggin, Chordin and Follistatin that blocks BMP signal that would otherwise dorsalize the mesoderm.

• In the presence of BMP activators the ectodermal cells form neural tissue.

• Wnt signalling causes a gradient of b-catenin along the anterior-posterior axis of the neural tube that appears to specify the regionalization of the neural tube.

Which one of the following statements related to components/features of senescence in plants is INCORRECT?

• Programmed cell death in plants may generate functional cells or tissues.

• Senescence can be induced by application of cytokinins and delayed by overexpression of salicylic acid

• Plants defective in autophagy demonstrate accelerated plant senescence

• Leaf senescence is regulated by NAC and WRKY genes families.

Which one of the following secondary metabolites is characterized by the presence of a central carbon atom that is bound by a sulphur to a glycone group, and by a nitrogen to a sulfonated oxime group?

• Alkaloids

• Terpenes

• Phenolics

• Glucosinolates