Answer:
Embryological evidence
Explanation:
Deuterostomes is a group that includes echinoderms, hemichordates, and chordates. Although these animals exhibit a wide variety of body plans, they share a mouth secondarily formed during embryo development, which it is believed to be an evolutionarily derived character present between a common ancestor and all its descendants (i.e., a synapomorphy). This oral cavity is formed by the invagination of the ectoderm layer opposite to the blastopore of the gastrula.
The main three theories are that - all organisms are composed of cells- the cell is the basic unit of structure and organization in organisms- All cells come from pre-existing cells
First, we want to know the average length of each cell. If you have 100 cells in a 1 millimeter space, we would do 1 ÷ 100. 1 ÷ 100 = 0.01 millimeters. Hope this helped!
