Q26.6-2ITD. Which organism has the most amin... [FREE SOLUTION]

Chapter 26: Q26.6-2ITD. (page 568)

Which organism has the most amino acids in common with the aphid? Rank the partial polypeptides from the other four organisms in degree of similarity to that of the aphid.

Short Answer

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Among the five tested organisms, the highest number of amino acids common to aphids was found in Ustilago (a fungus). Apart from this, the rest four organisms can be ranked based on the degree of similarity shown in their amino acid sequence.

Starting with the organism having the highest similarity after Ustilagoand moving in decreasing order, the organisms are: Gibberella, Staphylococcus, Pantoea, Arabidopsis.

Step by step solution

Evolution

Evolution can be explained as the biological process which accounts for the diversity in life forms. This phenomenon explains the relationship between different groups of organisms and how such diverse forms originated from the first life form. These differences and relatedness are represented in a phylogenetic tree.

Biosynthesis of amino acids

Amino acids are essential for the life process as they constitute proteins (a critical component of all biochemical processes). Among the different known amino acids, some can be synthesized within the body.

The biosynthesis of amino acids occurs through the translation of the genomic sequence, and thus, amino acids are also considered the decoded genomic information. The sequence of amino acids produced by different genomes is different and is also used for genetic analysis.

Relatedness of aphid’s sequence with other organisms.

The amino acid sequence for a carotenoid-producing polypeptide was noted in tabular form for aphid and 5 related organisms. Among these, the amino acid sequence of Ustilago(a fungus) had the highest similarity with the sequence of aphids (38 amino acids are similar).

The other four tested organisms also showed some similarities. In decreasing order of the sequence similarity with aphid, the organisms are as follows: Gibberella(35 similar amino acids), Staphylococcus(25 similar amino acids), Pantoea(20 similar amino acids), Arabidopsis(17 similar amino acids).