What is the classification based on chromosome number? A. Cytotaxonomy B. Numeral taxonomy C. Karyo-taxonomy D. Biochemical
Hint: Cytotaxonomy is the sub category of taxonomy based on living organisms which is based on cellular structure, meiotic behaviour and its structure.
Complete answer: Taxonomy is the branch of biology which deals with the naming and classification of different living organisms based on their characters, similarities and differences. Naming is given in the hierarchy and different groups are given ranks in an aggregated manner and further groups, sub-groups and sub-sub-groups are made for proper classification of all living organisms. Let’s talk about every given option one by one. Cytotaxonomy: It is a branch of taxonomy which deals with classification of living organisms based on studies of chromosomal pattern during meiosis. In this classification we use somatic cells and look at structure and behaviour of mitotic spindle and mitotic division. Numeral taxonomy: It involves the aggregation of living organisms based on their numerical methods of taxonomic units based on their characters and behaviour. It uses methods like cluster analysis irrespective of using subjective evaluation of their characters. Karyo-taxonomy: It is the classification based on properties of the nucleus of an organism. It includes structure of nucleus, pattern of chromosome, size and shape of chromosome, etc. This classification helps in obtaining phylogenetic relationships between different individuals and it also studies different bands patterns formed by chromosomes when stained with different dyes. Biochemical taxonomy: This taxonomy is also called chemotaxonomy because organisms are classified on the basis of similarities and differences of structure of chemical composition or chemical compounds of individuals.
So, after discussing all available options we can conclude that classification which is based on the number of chromosomes is Cytotaxonomy that is option ‘A’. Hence, Option ‘A’ is our answer.
Note: There is a small difference between Cytotaxonomy and Karyo-taxonomy, that is, Cytotaxonomy classifies on the basis of chromosome number, pattern and structure, but Karyo-taxonomy classifies organisms based on the characters of nucleus. Thus, we consider Cytotaxonomy as our answer.