Let me try
DNA Gel Electrophoresis is a huge topic
in this process actually what you are supposed to do is to try to get the DNA profile of the introns of the suspect, criminal or whoevers it is, this is a refrence profile that will be compared with the profile made by us only if it matches then the Suspect is said to be the criminal, that is done after you get your bands on the profile and then you compare the position of the bands.
this is not it, we can also use a gene probe to see the degree of hybridisation of DNA
as far as the process is concerned
you use restriction enzymes to cut the DNA at the specific base sequences, the DNA then goes through PCR
where the DNA is amplified(copied many times) going through a cycle of temperature changes
after this is done and remember this is done on the fragments of DNA.
NOW GEL ELECTROPHORESIS
it is a large tank with agarose gel and buffer solution in it, it has wells in one side and 2 electrodes are attatched to the tank, the nucleotides have been labelled with radioactive Nitrogen that will floresce under UV light or they are stained with ethidium bromide when there is a potential applied across the tank since phosphate group of nucleotide is negative it will move towards positive electrode or the anode another small dye is also put on the gel that is smaller then DNA fragments and when it reaches near to the cathode the electric supply is stopped -REMEMBER this fragments travel according to their size and charge
then comes Southern Blotting when you place nitrocellulose paper over the gel and wads of filter paper on top of it this will soak up all the gel and buffer solution leaving behind the fragments of DNA on the paper which can then be check for hybridisation with the gene probe if hybridisation between complementary base pair occurs at more than 11 sites then you confirm that you are sure of who the criminal is.
HOPE THAT EXPLAINS
now abundance of species is simply the number of species present in an ecosystem at any one time
just consider them as many different species
hope it is helpful for you, Pray for all of us
that our hardwork gets it reward ,INSHALLAH
there might be some mistakes you can look them up in books and correct them