The large number of antibodies that can be produced in a single individual is a result of a single b cell: producing multiple unique antibodies by genomic rearrangement. being able to produce unique antibodies from both the maternal and paternal alleles. producing a unique antibody from all other b cells by genomic rearrangement. secreting multiple antibodies that will be presented on the surface of other b cells.

The answer is; producing a unique antibody from all other B cells by genomic rearrangement.

An isolated B cell produces monoclonal antibodies (also called Immunoglobulins). Different B cell types produce different types of antibodies (hence the serum of an animal has polyclonal antibodies). Memory B cells are developed when a particular infection is eradicated by the immune system. These B cells proliferate when the infection returns by producing the same antibodies that were effective against the foreign entity.

11 males, 25%  

Explanation:

Eleven of the 44 males in this study are taller than 175 centimetres, which makes it one fourth of the total that is 25%. See below:  

simplify the fraction  

=  now multiply it by 100 to convert to a percentage value.

= 25%