Question

Make an ordered list of all the percent identity values from the table, starting with 100% at the top. Next to each number write the globin pair(s) with that percent identity value. Use one color for the globins from the α family and a different color for the globins from the β family. (a) Compare the order of pairs on your list with their positions in the model shown in Figure 21.14. Does the order of pairs describe the same relative “closeness” of globin family members seen in the model? (b) Compare the percent identity values for pairs within the α or β group to the values for between-group pairs.

Short answer

(a) From the given image, both α and β goblin genes are divided due to the mutation, and transposition also occurs. After transposition in two different chromosomes, both α and β goblin genes will go through duplications and mutations.

The data table also shows how all the phases change the values for percent identity depending on the different globin pairs.

(b) When the Gamma G gene pairs with Gamma A, the percent identity value is 99. The globin gene pair composed of alpha 2 and alpha 1 has the highest percent identity value, 100.

Step-by-step solution

Percent identity

The term percent identity defines a quantitative measurement. The measurement will depend on the similarities present between two sequences of amino acids or DNA or others.

A higher percent identity value indicates the species are closely related.Hence, percent identity values will reflect the relatedness between different species.

Explanation for ‘(a)’

Alpha 2 and alpha 1 pairs are closely related; that’s why the percent identity value is 100. The relativeness between alpha 1 with gamma A and gamma G pairs has the lowest percent identity. Less percent identity means less relatedness.

In the β-family, the beta and delta globin pair, the percent identity is 93, indicating a high amount of relativeness. Compared to epsilon, gamma A, and gamma G, the percent identity between epsilon and gamma A is 80.

Yes, the table shows the relative closeness between all the members present in the globin family.

Explanation for ‘(b)’

There is no percent identity between the members and indicates the absence of similarities between those members.

For example, there are no similarities between alpha 1 and alpha 1, delta and delta, gamma A and gamma A because percent identity applies when the sequences are different. When both the sequences are the same, the percent identity value is not justified.