Question

What is a monophyletic group of organisms?

a) Groups that include several lineages that do not share a common ancestor.
b) Groups that include the common ancestor and only one descendent of that common ancestor.
c) Group that includes the common ancestor plus some but not all descendants of that common ancestor.
d) Groups that include the common ancestor and all descendents of that common ancestor.

Answer 1

A monophyletic group or clade includes the common ancestor and all its descendants, representing a true segment of evolutionary history on the phylogenetic tree.

Step-by-step explanation:

A monophyletic group of organisms, also known as a clade, is a group that includes a single common ancestor and all of its descendants. This concept is fundamental in the field of evolutionary biology as it helps in understanding the phylogenetic relationships between organisms. A clade is a key component of a phylogenetic tree, which is a diagrammatic representation of these evolutionary relationships, illustrating how different species or groups of organisms are related through common ancestry.

The correct answer to the question is: d) Groups that include the common ancestor and all descendants of that common ancestor. This definition ensures that the group is a true representation of organisms descending from a single point in the evolutionary history, known as a node on the phylogenetic tree.