Question

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. All members of a species can potentially interbreed. A) I and II B) I and III C) II and III D) I, II, and III

Answer 1

Option B is the correct answer.

Biological species are defined by reproductive isolation. This fact is true. An organism from a certain species will mate with an organism from the same species every time and thus they can give birth a healthy, fertile organism in normal environment. This is not true that an organism of a certain species can't mate with an organism from another species, they can mate but their mating can't give birth a healthy and fertile successor organism.

For an example-- if a male horse and a female donkey mate with each other then the mother will give birth a hybrid called mule. The mule is healthy and lives a long life, but it is not fertile and can't give birth successor.

So we see, reproductive isolation is very common in a species.

The second fact that says biological species are the model used for grouping extinct form of life is not correct. There are many groups of organisms that are living in this world and they are differentiated into many species according to their different characteristics.

The third point which says all members of a species can potentially interbreed is correct or true. All members of a species can interbreed among themselves whenever they become adults.

So here we can see Option B is the right answer.