Question

Three living species X, Y, and Z share a common ancestor, T, as

do extinct species U and V. A grouping that consists of species

T, X, Y, and Z (but not U or V) makes up

(A) a monophyletic taxon.

(B) an ingroup, with species U as the outgroup.

(C) a paraphyletic group.

(D) a polyphyletic group.

Short answer

(A) The option “a monophyletic taxon” is false.

(B) The option “an ingroup, with species U as the outgroup” is false.

(C) The option “a paraphyletic” is true.

(D) The option “a polyphyletic”isfalse.

Step-by-step solution

Extinct Species

The term extinct species indicates those species which do not exist in the world anymore. It can be due to many factors, such as evolutionary problems and human interference. Some of the extinct species include the Dodo and the Tasmanian tiger.

Explanation of option (A)

The monophyletic taxon is a taxon that consists of a group of organisms consisting of a common ancestor and all its descendants. It must include U and V also in its group of organisms.

Thus, a group that consists of only T, X, Y, Z species but not U and V do not make up the monophyletic group.

Therefore, the given statement is false.

Explanation of option (B)

As per the question, U and V are extinct species. They also share a common ancestor, T, as shared by X, Y, Z. So, X, Y, Z cannot be considered as an ingroup. Ingroups include a group of organisms with evolutionary relationships.

Thus, the group that consists of only T, X, Y, Z species but not U and V do not make up ingroup.

Therefore, the given statement is false.

Explanation of option ‘(C)’

The organisms that contain the most common ancestor belong to one of the groups are a paraphyletic group. It also includes some descendants of ancestors, not all. Some of the examples of this group are Reptilia, such as snakes and lizards.

Thus, a group that consists of only T, X, Y, Z species but not U and V make the paraphyletic group.

Therefore, the given statement is true.

Explanation of option ‘(D)’

The group of organisms that do not consist most recent ancestor belongs to the polyphyletic group. So, it must lack ancestor Its examples are a group of flying vertebrae.

Thus, the group that consists of only T, X, Y, Z species but not U and V make does not make the polyphyletic group.

Therefore, the given statement is false.