Innate immune response is targeted towards a specific group of pathogens.

Pathogens engulfed by macrophages are degraded by enzymes present in the cytoplasm of the macrophage.

Antigen presenting cells (APC) present antigens on MHC class I to naïve CD4 T cells and B cells.

B cell maturation occurs in the blood whereas T cell maturation occurs in the trachea.

One of the signals required for the activation of naive CD4 T cells is the binding of CD28 protein on CD4 T cells with CD80 protein on the APC.

Cytotoxic-T cells release granzymes and perforin to kill cells infected by pathogen.

During B cell clonal selection and expansion, cells with a very high affinity for the antigen will divide and differentiate into plasma cells.

Antibodies are glycoproteins with a tertiary structure.

The B cell receptors of a B cell and the antibodies released by that B cell after activation recognise different antigens.

IgG is the first class/type of antibody produced during a humoral response.

Somatic recombination of the heavy and light chain genes of B cells occurs during mRNA splicing.

Somatic hypermutation allows antibodies to recognise a wider range of antigens.

Class switching involves changes made to the DNA segments coding for constant region of the heavy chain.