Inversion of DNA sequences within chromosomes is a common process in evolution. The following gene arrangements in a particular
chromosome are found in four different species: First sequence: ABCDEF
Second sequence: ABFEDC
Third sequence: FEDABC
Fourth sequence: ADEFBC
Assuming that the arrangement in the first sequence is the ancestor/reference arrangement, in what evolutionary order did the four species arise, such that the fewest number of inversions occur between each species (place the first sequence as the earliest species in your ordering)?
The correct answer is "Fist sequence; Fourth sequence; Second sequence; Third sequence".
Explanation:
Inversion of DNA is a process that often occurs during evolution of chromosomes. It occurs when the breakage of a chromosome in two places, results in the reinsertion of a DNA but in a reversed fashion. The evolutionary order of predecessors of inversion of DNA can be established by looking on the number of nucleotides that are different in the sequences of DNA. In this case, the first sequence is the ancestor and it haves the sequence "ABCDEF". The second in the evolutionary order is the fourth sequence since it originates from the first sequence only by changing the "BC" nucleotides to the end of the sequence "ADEFBC". The third in the evolutionary order is the second sequence since it still starts in AB, but has the other four nucleotides different: "ABFEDC". The last in the evolutionary order is the third sequence, which is completely different and reversed respect to the first sequence: "FEDABC".
The process of cell division that reduces the number of chromosomes is That the number of chromosomes per cell is cut in half through the separation of homologous chromosome in a diploid cell
A logging company promises to plant five trees for every one of them that it cuts down. You may or may not have seen a forest affected by acid rain. The trees are stripped of leaves and branches and the whole forest appears to be like it's dying, which it is. Acid rain is caused by air pollution and has a very harmful effect on plant and animal life, any life really.
