Chapter 19, Problem 5STP

Summary Introduction

Introduction :

A species is a basic unit of classification thus the species concept is used by taxonomists and evolutionary biologists to define a species. Members of one species are reproductively isolated from the members of another species. 

The phylogenetic species concept is a highly dynamic system and used to define species based on the details of ancestry. Characteristics of a species include common ancestry, resemblance, anatomical similarities, etc.

Answer to Problem 5STP

Correct answer :

Option (D) morphological characters.

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) morphological characters. Bone characteristics of the two birds are used to define a species with morphological features in common and separable from other species. Morphological discontinuities are used to separate the individuals of two different species. 

Explanation for incorrect answer :

Option (A) biochemical characters. These characters are based on the chemical constitution, biochemical reactions, and body functions. They are used as evidence that is based on biochemistry and comparative physiology. Hence, it is an incorrect answer.

Option (B) cellular characters. These characters are based on the structure and function of the cells. The cellular components involved in biochemical pathways. Hence, it is an incorrect answer.

Option (C) chromosomal characters. These characters are based on the chromosome complement of a cell. Some of the chromosomal aspects involved are number, size, length of the arm, and centromeric ratio, the position of the centromere, etc. Hence, it is an incorrect answer.