The radial symmetry and mesodermal skeleton in echinodems
Bilateral symmetry and internal skeleton of chordates
Explanation:
The echinoderms have radial symmetry and their skeleton is mesodermal made up of calcites known as ossicles while the chordates have bilateral symmetry and their internal skeleton is made up of bones and cartilages.
Using the population we can get a wider variety of sample sizes.
Outcomes for any given situation can be drastically changed based on the individual put in that situation. Thus, we use the whole population to cover a wider range of possibilties.
