Question

difference between classical taxonomy and modern taxonomy

Answer 1

Taxa means arrangement and nomos means law. Taxonomy is the branch of science that deals with the study of classifying organisms.
Classical Taxonomy:
1- Species is taken as basic unit or a fixed entity .
2- It is also called old taxanomy.
3-External features are focused.
4 Species is emphasized.
Modern Taxonomy:
1- Species is considered as dynamic entity.
2- Also called as Neo-systematics.
3- Morphological features are not considered rather biological delimitation is focused. Evolutionary history of organism is studied.
4- Population or sub-species is emphasized.

Answer 2

Classical Taxonomy :
It is called old taxonomy or systematic.
It is from earliest times to the time of Carolus Linnaeus.
Few individuals were studied.
Practical, artificial and natural systems was proposed.
The species was delimited on morphological characters

Modern Taxonomy :
It is called Neosisystematics or Biosystematic.
It is from post Linnean periods. Its concept was given by Julian Huxley 
Large number of individuals are studied.
Morphological delimitation was replaced by biological delimitation.