Which of the following is based upon the principle of antigen-antibody interaction ?
$PCR$
$ELISA$
$r-DNA$ technology
$RNA$
The main reason why antibiotics could not solve all the problems of bacteria mediated diseases is
‘Pathogens' were discovered by
Give differences : $B-$ lymphocytes and $T-$ lymphocytes
Spread of cancerous cells to distant sites is termed as
Neurosis is characterised by