Dna samples should be stored in an airtight containers to prevent contamination true or false

True

Explanation:

DNA is a biological evidence. It is a heredity material which is present in all organisms on earth. The DNA in humans can be taken as sample from nails, bones, blood, skin, hair and other sources.

The DNA samples can be taken so as to establish the identity of the culprit, victim or any one which is associated with crime.

The DNA evidence has applicability as a potent evidence in the court of law. Thus utmost care should be taken to preserve it's integrity until it is analysed and presented in the court of law.

Thus the DNA evidence should be collected and preserved in airtight containers so as to prevent the entry of airborne pathogens like bacteria, virus these can contaminate the sample evidence and can make the evidence not of any use.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion