How similar do DNA sequences need to be for 2 organisms to be considered the same species? And how is this decided

What does all of the organ system in a human form

The table lists the observations students made about four specimens under a microscope. based on these observations, what specimens did the students examine? animal plant virus prokaryote cell membrane present ribosomes present lysosomes present nuclear membrane present cell wall present ribosomes present nuclear membrane absent cell wall present ribosomes present nucleus present large vacuole present reproduces inside of a cell nucleus absent rna present 2019 edmentum all rights reserved intl

In general, are there any major differences that you can see? explain