Alloploids are sterile. Hence, though they might be fertile between their own cross but cannot interbreed with either of the parent species, thus getting reproductively isolateD.In alloploidy, when two different species interbreed, their chromosomes combine resulting in the formation of a polyploidy hybrid. During meiosis of this polyploidy hybrid, an error occurs due to the absence of homologous pair of chromosomes for each of the chromosome derived from the parent. This thus results to hybrid sterility as the offspring produced by this hybrid would be aneuploid hence rendering it inviable. Thus, alloploids are reproductively isolated from the parent species due to hybrid sterility.
Allotetraploids on the other hand inherit even number of chromosomes from the parents. As a result, during meiosis, they have homologous set of chromosomes that pair up and hence do not from sterile aneuploid cells.
The technique that is most commonly used to amplify and increase the amount of DNA (deoxyribonucleic acid) is the PCR (polymerase chain reaction). By this technique, it is possible to create any number of strands from a single strand of DNA.The method of this technique includes several steps:
• Denaturation: This is the first step of the PCR technique. In this step, the strand of DNA is heated to 94 - 98 o C for 20-30 seconds. This process breaks the hydrogen bond present between the bases of two strands of DNA and results in the formation of single stranded DNA molecules.
• Annealing: In this step, the primers are introduced in the reaction. Hence the temperature of the reaction is lowered to 50 - 65 o C that aids in the formation of hydrogen bonds between the primer and single stranded DNA. The DNA polymerase that is present binds to this hybrid template and begins the process of DNA formation.
• Elongation: In this step, the DNA polymerase synthesizes a complementary DNA strand to that of the original single stranded DNA. This process continues until the required length or numbers of DNA strands are produced.
By producing complementary strands of the available DNA strand over and over again until the reaction is stopped, the DNA polymerase along with the primer and original DNA template helps in increasing the amount of a specific region of DNA.
Since the populations of the snakes are separated by a physical barrier, thus there might be a possibility of reproductive isolation amongst them. Thus, some of the best ways to determine, if the two species of snakes are members of the same or different species, are:
• Watching the two populations of snakes in nature, by sitting in a hidden spot, and observing if the eastern and western snakes interbreed in their natural environment.
• The next step could be to breed them in captivity and observe if they mate with each other in captivity.
• The best method of all would be to read and assess the chromosome structure and number for any differences present if any by karyotyping.