Question

Species endangered but with unknown cause is
A. Rare
B. Vulnerable
C. Intermediate
D. Indeterminate

Answer 1

Hint:
Species, in biology, classification comprising related organisms that share common characteristics and are capable of interbreeding. An example of a species is all human beings.

Complete answer:
Species have the largest no. Of organisms with maximum common characteristics.
The Biological Species Concept defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring.
Endangered species, any species that is at risk of extinction because of a sudden rapid decrease in its population or a loss of its critical habitat.

> RARE:- A rare species is a group of organisms that are very uncommon, scarce, or infrequently encountered. So , this option is incorrect.

> VULNERABLE:- These are the species whose population has declined to levels from where it is likely to move into the endangered category in the near future if the negative factors continue to operate such species. The examples of such species are Blue sheep. Hence, this option is also incorrect.

> INTERMEDIATE:- And intermediate species is one that exists between an ancestral form of an organism and a more modern form. So, this option is wrong.

> INDETERMINATE:- The species that is endangered but the cause is not known are known as indeterminate species. So, this option is correct.

Our correct option is D that is indeterminate species.

Note:
The indeterminate species are those species which are considered under the category of threatened species. Such species are defined under the IUCN red book data as the species which are under the threat. These species cannot be categorized into extinct, vulnerable, endangered and rare categories appropriately.