Category: SCIENCE VIDEO

This video is about the salient features of chordata. Presence of notochord, Dorsal tubular nerve cord and pharyngeal gill slits, post anal tail are the basic features of chordate, which should be present in any of the stages of life or throughout the lifetime. Ascidiaceae possess these characters in larval stage, branchiostoma throughout life time, and in higher chordates notochord is replaced with vertebral column, pharyngeal gill slits modified for aerial respiration and the nerve cord is modified into Central Nervous System.

This video is about the morphology of the chromosome. Chromosomal body has elongated highly coiled DNA fibrils known as chromonema which are embedded in the matrix and matrix is covered with the pellicle. The size, shape and number of chromosome are fixed according to species. Organism having one set of chromosome are Haploid(n), with double set they are diploid, more than two set are known as polyploids.