Two diploid species of closely related frogs, which we will callspecies A and species B, were analyzed with regard to the genesthat encode an enzyme called hexokinase. Species A has two distinctcopies of this gene: A1 and A2. In other words, this diploidspecies is A1A1 A2A2. Species B has three copies of the hexokinasegene, which we will call B1, B2, and B3. A diploid individualof species B would be B1B1 B2B2 B3B3. These hexokinase genesfrom the two species were subjected to DNA sequencing, and thepercentage of sequence identity was compared among these genes.The results are shown here. Percentage of DNA Sequence Identity A1 A2 B1 B2 B3A1 100 62 54 94 53A2 62 100 91 49 92B1 54 91 100 67 90B2 94 49 67 100 64B3 53 92 90 64 100 If we assume that hexokinase genes were never lost in the evolutionof these frog species, how many distinct hexokinase genesdo you think there were in the most recent ancestor that precededthe divergence of these two species? Explain your answer. Alsoexplain why species B has three distinct copies of this gene,whereas species A has only two.
Two diploid species of closely related frogs, which we will call
species A and species B, were analyzed with regard to the genes
that encode an enzyme called hexokinase. Species A has two distinct
copies of this gene: A1 and A2. In other words, this diploid
species is A1A1 A2A2. Species B has three copies of the hexokinase
gene, which we will call B1, B2, and B3. A diploid individual
of species B would be B1B1 B2B2 B3B3. These hexokinase genes
from the two species were subjected to DNA sequencing, and the
percentage of sequence identity was compared among these genes.
The results are shown here.
Percentage of DNA Sequence Identity
A1 A2 B1 B2 B3
A1 100 62 54 94 53
A2 62 100 91 49 92
B1 54 91 100 67 90
B2 94 49 67 100 64
B3 53 92 90 64 100
If we assume that hexokinase genes were never lost in the evolution
of these frog species, how many distinct hexokinase genes
do you think there were in the most recent ancestor that preceded
the divergence of these two species? Explain your answer. Also
explain why species B has three distinct copies of this gene,
whereas species A has only two.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
