Question

The species are called sibling, if there is

• A. Practically no morphological distinction
• B. No morphological distinction but reproductive isolation with biological characters
  
• C. Reproductive isolation produced due to geographical isolation
• D. Both B and C
• E. None of the above

Answer 1

Answer: (B)

No morphological distinction but reproductive isolation with biological characters

One of two or more individuals having one or both parents in common. Typically, a brother or a sister. Many societies choose not to differentiate children who have both parents in common from those who share only one parent, all are known simply as siblings. So, the species are called sibling, if there is practically no morphological distinction but possess biological characters and are reproductively isolated.

So, the correct answer is option B.