Immunity

Step 1: Understanding B-lymphocyte activation.
When B-lymphocytes are activated, they proliferate and differentiate into plasma cells. These plasma cells secrete antibodies that are specific to the antigen that triggered the immune response.
Step 2: Analyzing the options.
(A) cytotoxic T-cells, B-perforins: Incorrect. Cytotoxic T-cells and B-perforins are not directly involved in this process.
(B) plasma cells, B-antibodies: Correct. Activated B-lymphocytes differentiate into plasma cells, which produce antibodies.
(C) plasma cells, B-antigens: Incorrect. Plasma cells produce antibodies, not antigens.
(D) memory T-cells, B-lymphokines: Incorrect. Memory T-cells are involved in long-term immunity, but they do not directly produce antibodies.
Step 3: Conclusion.
The correct answer is (B) plasma cells, B-antibodies, as B-lymphocytes differentiate into plasma cells that produce antibodies.

Step 1: Understanding acquired immunity.
Acquired immunity is characterized by specificity (targeting specific pathogens), memory (ability to remember pathogens for quicker responses), and diversity (ability to respond to various antigens). Non-specificity is a feature of innate immunity, not acquired immunity.
Step 2: Analyzing the options.
(A) Discrimination between self and non-self: Incorrect, this is a key feature of acquired immunity.
(B) Non-specicity: Correct, non-specificity is not a feature of acquired immunity, which is highly specific.
(C) Memory: Incorrect, memory is a defining characteristic of acquired immunity.
(D) Diversity: Incorrect, acquired immunity has the ability to respond to a wide variety of antigens.
Step 3: Conclusion.
The correct answer is (B) Non-specicity, as it is a characteristic of innate immunity, not acquired immunity.

Step 1: Understanding the function of lysozyme.
Lysozyme is an enzyme found in bodily fluids such as tears, saliva, and mucus. It breaks down the cell walls of bacteria, causing them to lyse (burst).
Step 2: Analyzing the options.
(A) bacteria: Correct. Lysozyme is primarily responsible for breaking down bacterial cell walls.
(B) fungi: Incorrect. Lysozyme is not effective against fungi.
(C) protists: Incorrect. Lysozyme does not target protists.
(D) viruses: Incorrect. Lysozyme does not act on viruses.
Step 3: Conclusion.
The correct answer is (A) bacteria, as lysozyme is effective in lysing bacterial cells.