There are limitations to applying the Biological Species Concepts, based on its criteria, so in some cases it is actually better to use the Morphospecies Concept. Which of the following would require being defined using the Morphospecies Concept instead of the Biological Species Concept?
a. Birds b. Dinosaurs c. Insects d. Mammals e. Flowering plants

The correct option is E ( flowering plants).

Explanation:

Morphological specie concepts are concepts that uses the differences in morphological characters to distinguish species.

Biological species concept is the concept that describes species as group of individuals that can interbreed and produce fertile offspring. This was invented in 1942 by Ernst Mayr. Although this concept is considered optimal for definition of species, it has limitations which includes:

- It can't be used to classify plants due to incomplete separation of evolutionary lineages. Therefore flowering plants require being defined using the Morphospecies Concept instead of the Biological Species Concept.

- it can't be applied in organism which reproduce only asexually ( that is, their sexual reproduction is unknown).

the answer is d. chordata