Question

Which of the following is untrue about the Unweighted Pair Group Method Using Arithmetic Average?

(a) The simplest clustering method is UPGMA, which builds a tree by a sequential clustering method

(b) Given a distance matrix, it starts by grouping two taxa with the largest pairwise distance in the distance matrix

(c) The distances between this new composite taxon and all remaining taxa are calculated to create a reduced matrix

(d) The grouping process is repeated and another newly reduced matrix is created

The question was asked in quiz.

The query is from Distance Based Methods topic in portion Phylogenetic Tree Construction Methods and Programs of Bioinformatics

Answer 1

Correct choice is (b) Given a distance matrix, it starts by grouping two taxa with the largest pairwise distance in the distance matrix

Explanation: It starts by grouping two taxa with the smallest pairwise distance in the distance matrix. A node is placed at the midpoint or half distance between them. It then creates a reduced matrix by treating the new cluster as a single taxon.