Question

Many studies depend on eDNA to collect samples from aquatic environments because:

A. DNA disperses and remains free floating in a body of water

B. An electric current is run through water to collect negatively charged DNA

C. They are less likely to show false positives or false negatives

D. DNA clumps when in an aqueous solution and clumps are easy to collect

Answer 1

Answer is A

A. DNA disperses and remains free floating in a body of water.

Explanation: eDNA (Environmental DNA) is DNA collected from various environmental sites such as soil, seawater, air etc. It is not collected directly from the environment. eDNA will come out in the water by faeces and secretory materials from the body of organism. eDNA will be collected by scientist to know the presence of particular species in that region or presence of any mutations or for other research purposes. DNA will be floating on the water bodies therefore it gives advantage of collection of DNA. It can be collected simply by collecting water from the shore or surface.

Explanation form the wrong answers.

B. Running of electric current through water will not give any extra advantage for sample Collection when sampling process is simple (explained above). Additionally, introduction of current in the water may be harmful for other creatures.

C. If you want to sample eDNA to know the presence of species in particular region. Aiming that you have collected DNA from the water surface. However, because of water current and stability of DNA, it might be possible that DNA come from travel long distance and hence your aim will not fulfilled and whatever result will come, though they are technically correct; will give false positive information.

D. DNA will forms clump in alcohol (ethanol) not in aqueous solution.