Pakupanga mankhwala ndi kafukufuku wa labu, ntchito imodzi yofunika kwambiri ndikutulutsa zosungunulira, mankhwala, kapena mayankho. Kaya ndikuyika, kuyeretsa, kapena kukonzekera zitsanzo, kutulutsa madzi ndi gawo lofunikira kwambiri pazasayansi ndi mafakitale.