what are the major divisions in the plantae ? what is the basis for these divisions?

The major divisions of Plantae are:

Thallophyta

Bryophyta

Pteridophyta

Gymnospermae

Angiospermae

Among plants, the first level of classification is based on whether or not the plant body has well differentiated, distinct body parts. Plants lacking well-differentiated body parts belongs to division Thallophyta.

 

 

The next level of classification is based on whether the differentiated plant body has specialized vascular tissues, i.e. xylem and phloem, for the transport of water and other substances within it. Bryophyta shows a differentiated plant body but without vascular system. Those plants having a well-differentiated body and vascular tissues belongs to division Pteridophyta.

 

The further classification is done on the basis of the ability to bear seeds and whether the seeds are enclosed within fruits. So, the well differentiated plants with vascular tissues are further divided into two categories, those which do not produce seeds and those which produce seeds. Pteridophytes do not produce seeds.

 

 

Plants which do produce seeds come under the category of Phanerogams. Phanerogams either bear naked seeds or the seeds are present within fruits. Those bearing naked seeds belong to Gymnospermae whereas division Angiospermae bear seeds inside fruits.