1) How would be choose between two characteristics to be used for developing a hierachy in classification?
2) Explain how animals in vertebrates are classified into further sub-groups.
To develop a hierarchy of classification, first we need to decide or select two characteristics, which can make a broadest division. Then we take another set of characteristics for further dividing subgroups under these divisions. We can choose fundamental as well as other characteristics to develop hierarchy of classification. For example there is a feature, locomotion, which can be considered as the basic characteristics for distinguishing plants from animals. Plants lack locomotion. Thus on the basis of this character we get two broad divisions plants and animals. Other characteristics like presence of chlorophyll and cell wall are other set of characteristics which can be used to create the hierarchy of classification.
2) Vertebrates are classified into further subgroups on the basis of several characteristics
For example Pisces are class of animals having two chambered heart, a paired gills for taking in, dissolved oxygen and have a cold blooded feature. Another class Mammalia and Aves can be distinguished from Pisces, as they have four chambered heart and are warm blooded. But there are some other features that differentiate Aves from Mammalia, such as in birds fore limbs are modified into wings. they have hollow bones and skin covered with feathers. We can use various other features also for creating other groups ( classes ) among vertebrates.
In this way, vertebrates are classified into various classes such as Reptilia, Amphibia , Aves, Mammalia and Pisces
2) Vertebrates are classified into further subgroups on the basis of several characteristics
For example Pisces are class of animals having two chambered heart, a paired gills for taking in, dissolved oxygen and have a cold blooded feature. Another class Mammalia and Aves can be distinguished from Pisces, as they have four chambered heart and are warm blooded. But there are some other features that differentiate Aves from Mammalia, such as in birds fore limbs are modified into wings. they have hollow bones and skin covered with feathers. We can use various other features also for creating other groups ( classes ) among vertebrates.
In this way, vertebrates are classified into various classes such as Reptilia, Amphibia , Aves, Mammalia and Pisces