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

C. a paraphyletic group.

Explanation:

When referring to phylogeny a group can be considered paraphyletic when it includes the common ancestor, but it does not include all the descendants from this common ancestor.

The group is (T, X, Y, and Z), the other group is (U and V) and they both share a common ancestor (T).

The use of paraphyletic group is still controversial. Some accepted and other don't.

what's the

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.