A twin is one of two offspring produced in the same pregnancy and developed from one oocyte (monozygotic) or from two oocytes (dizygotic) fertilized at the same time. Dizygotic twins or fraternal twins are heterologous twins developed from two separate oocytes fertilized at the same time. They may be of the same or opposite sex, differ both physically and genetically, and have two separate and distinct placentas and membranes, both amnion and chorion. These twins can accept grafts from each other as they have identical MHC haplotypes and identical T_H cells.

Correct Option: D

A twin is one of two offspring produced in the same pregnancy and developed from one oocyte (monozygotic) or from two oocytes (dizygotic) fertilized at the same time. Dizygotic twins or fraternal twins are heterologous twins developed from two separate oocytes fertilized at the same time. They may be of the same or opposite sex, differ both physically and genetically, and have two separate and distinct placentas and membranes, both amnion and chorion. These twins can accept grafts from each other as they have identical MHC haplotypes and identical T_H cells.

Lymphocytes constitute 20- 40% of the body’s white blood cells and 99% of the cells in the lymph. Lymphocytes continually circulate in the blood and lymph and are capable of migrating into the tissue spaces and lymphoid organs, thereby integrating the immune system to a high degree. Lymphocytes interact with foreign antigens in lymph nodes. Lymph nodes are the sites where immune responses are mounted to antigens in lymph. They are encapsulated bean shaped structures containing a reticular network packed with lymphocytes, macrophages, dendritic cells. Lymph nodes are the first organized lymphoid structure to encounter antigens that enter the tissue spaces.

Correct Option: D

Lymphocytes constitute 20- 40% of the body’s white blood cells and 99% of the cells in the lymph. Lymphocytes continually circulate in the blood and lymph and are capable of migrating into the tissue spaces and lymphoid organs, thereby integrating the immune system to a high degree. Lymphocytes interact with foreign antigens in lymph nodes. Lymph nodes are the sites where immune responses are mounted to antigens in lymph. They are encapsulated bean shaped structures containing a reticular network packed with lymphocytes, macrophages, dendritic cells. Lymph nodes are the first organized lymphoid structure to encounter antigens that enter the tissue spaces.

A neonatally thymectomized mouse, appeared healthy until about 2 to 4 months of age. Thymectomy after 3 weeks of age was not associated with any significant impairment of homograft immunity.

Correct Option: B

A neonatally thymectomized mouse, appeared healthy until about 2 to 4 months of age. Thymectomy after 3 weeks of age was not associated with any significant impairment of homograft immunity.

NA

Correct Option: C

NA

Hybridoma technology is used to combine the properties of site specific antigen activity of B cells with the immortality property of Myeloma M (cancerous) cells. Thus, the cells from a successful hybridoma experiment have single specificity of B cells with indefinite life span property. Anitbodies therefore produced are all of single specificity and hence are monoclonal in nature. Using monoclonal Ab’s, cells are categorised on the basis of expression of certain defined markers. Prostate specific Ag and other organ-associated Ag are used with the produced monoclonal Ab for determining nature of a primary tumour. 38.Interferon beta is produced mainly by fibroblasts and some epithelial cell types. The synthesis of IFN beta can be induced by common inducers of interferons, including viruses, double- stranded RNA, and bacteria. It is also induced by some cytokines such as TNF (Tumor Necrosis Factor) and IL1 (Inter Leukin1).

Correct Option: A

Hybridoma technology is used to combine the properties of site specific antigen activity of B cells with the immortality property of Myeloma M (cancerous) cells. Thus, the cells from a successful hybridoma experiment have single specificity of B cells with indefinite life span property. Anitbodies therefore produced are all of single specificity and hence are monoclonal in nature. Using monoclonal Ab’s, cells are categorised on the basis of expression of certain defined markers. Prostate specific Ag and other organ-associated Ag are used with the produced monoclonal Ab for determining nature of a primary tumour. 38.Interferon beta is produced mainly by fibroblasts and some epithelial cell types. The synthesis of IFN beta can be induced by common inducers of interferons, including viruses, double- stranded RNA, and bacteria. It is also induced by some cytokines such as TNF (Tumor Necrosis Factor) and IL1 (Inter Leukin1).