Which of the following set of cell organelles are involved in the biosynthesis of jasmonic acid through octadecanoid signaling pathway?

• Chloroplast and peroxisomes  

• Chloroplast and mitochondria   

• Mitochondria and peroxisomes  

• Golgi bodies and mitochondria  

Indirect immunofluorescence involves flurorescently labeled

• Immunoglonulin-specific antibodies 

• Antigen-specific antibodies 

• Hapten-specific antibodies 

• Carrier-specific antibodies  

Maturation-promoting factor (MPF) controls the initiation of mitosis in eukaryotic cells. MPF kinase activity required cyclin B. Cyclin B is required for chromosome condensation and breakdown of the nuclear envelope into vesicles. Cyclin B degradation is followed by chromosome decondensation, nuclear envelope reformation and exit from mitosis. This required ubiquitination of a cyclin destruction box motif in cyclin B. RNase-treated Xenopus egg extracts and sperm chromatin were mixed. MPF activity increased with chromosome condensation and nuclear envelope breakdown. However, this was not followed by chromosome decondesation and nuclear envelope reformation because

• RNase contamination persisted in the system   

• Cyclin B was missing from the system  

• Ubiquitin ligase had been overexpressed 

• Cyclin B lacking the cyclin destruction box had been overexpressed 

Many cancers carry mutant p53 genes, while some cancers have normal p53 genes, p53activates p21 (Wad1) which inhibits G1/S-Cdks and phosphorylation of the retinoblastoma protein (Rb). Cancers with normal p53genes could

• Express non-phosphorylatable form of Rb  

• Express high levels of p53-deubiquitinases 

• Express inactive forms of  G1/S-Cdks  

• Express inactive forms of G1/ S cyclins  

A fixed smear of a bacterial culture is subjected to the following solutions in the order listed below and appeared red.

(a)Carbolfuchsin (heated)

(b)Acid-alcohol 

(c)Methylene blue

Bacteria stained by this method can be identified as

• Non-acid fast E.coli   

• Acid-fast Mycobacterium sp.  

• Gram positive E.coli    

• Gram-negative  Mycobacterium sp. 

26.

Intracellular transport and cytoskeletal organization of a cell is regulated by nucleotide exchange of different small molecular weight GTPases of Ras super family. Overexpression of which of the following GTPase modulates the actin-cytoskeleton of HeLa’cells?

• Ran in GDP bound form  

• Ran in GTP bound form  

• Rho in GTP bound form 

• Rho in GDP bound form  

Tumor cells were isolated from a breast cancer patient. These cells were injected into nude-mice and they were divided into four groups. Group 1 received EGF receptor-conjugated with ethotrexate; Group 2 received transferin receptor-conjugated with methotrexate; Group 3 received mannose receptor-conjugated with methotrexate; Group 4 received same amount of the free drug. In which of the following cases tumorigenic index would be minimum?

• Free drug 

• EGF receptor-conjugated drug  

• Transferrin receptor-conjugated drug  

• Mannose receptor-conjugated drug  

Viral gene expression after T3 bacteriophage infection is controlled by:

• Repressor molecule

• Slow injection of nucleic acid        

• Modification of RNA Polymerase

• DNA Polymerase

Which of the following factors is NOT true for the low levels of immune response in Plasmodium infection?

• Different types of antigens are expressed at various stages of Plasmodium life cycle.

• Most of the phases in the life cycle of Plasmodium are intracellular.

• Sporozoites are rapidly cleared from blood circulation.

• Plasmodium infection primarily destroys macrophages and dendritic cells.

Presence of the nuclear localization signal (NLS) in a steroid receptor indicates that the receptor resides

• On the nuclear membrane

• Within the nucleus

• On the cell membrane  

• In the cytosol