Chikungunya is caused by chikungunya virus. Colostrum is the first breastmilk of mother, which contains antibodies (especially Ig $A$). It provides immunity to infants against various pathogens. Beer is manufactured by the fermentation of barley malt by yeast. Tissue culture can be used to obtain virus-free healthy plants from diseased plants. It is because of the fact that meristematic cells are undifferentiated in nature.