Answer: 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.
Dominant' traits will actually disappear faster if they are disadvantageous.
Think about it: if everyone who has even a single copy of a particular allele is at a disadvantage (manifests the phenotype, in this case six fingers), then even single copies are selected against.
In the case of recessive traits, selection occurs only against homozygous carriers, who may be very rare if the allele itself is rare.
A concrete example would be something like Tay-Sachs disease. If the allele that causes this were dominant, every carrier would die before adulthood, and it would occur only as a very rare de novo mutation. But because it is recessive, it persists for now; heterozygous carriers have no disadvantage.
Answer:
blood flows through pores in the tissues