Three organisms have part of a gene for a digestive enzyme sequenced, and homologous parts of those sequences are shown below. One organism is a fungus and the other two are green algae.
Organism | Sequence
1 | AGATTCGATTCGCTTTAAA
2 | ACAGTCGAT_CGGCATAAA
3 | AGAT_CGATTCGGTTTAAA
Based on this data, identify which organisms are which and explain why.
Based on the given data, we can determine which organisms are the fungus and the green algae based on the homologous sequences.
From the sequences, we can identify a specific pattern in the second organism's sequence. In the first and third organisms, the sequence is "AGATTCGATTCGCTTTAAA," whereas in the second organism, there is one difference, "ACAGTCGAT_CGGCATAAA."
Looking at the character that differs, we see that in the first and third organisms, it is a "T," whereas in the second organism, it is an underscore "_". This suggests that the underscore "_" in the second organism's sequence is a deletion or gap in the alignment.
Next, we can compare the sequences of the first and third organisms, which match perfectly except for the sixth character, where the first organism has a "T," and the third organism has a "C." This indicates a single nucleotide polymorphism (SNP) or a mutation between the two organisms.
Based on this information, we can conclude that the second organism is a green alga, as it contains a deletion or gap in the alignment. The first and third organisms are likely the fungus and the other green alga, respectively, as they have mostly identical sequences except for a single nucleotide polymorphism (SNP) between them.
In summary:
- Organism 1: Fungus
- Organism 2: Green Alga
- Organism 3: Green Alga