Sponges absent
Cnidarians not jointed (Aquatic organisms, all have tentacles with nematocysts - stinging cells, used to capture food.)
Roundworms absent (AKA nematodes are unsegmented, colorless and do not have appendages).
Annelids not jointed (With the exception of leeches, all annelids have chitonous hair-like structures projecting from their cuticle. These appendages fulfill different functions in different species.)
Mollusks not jointed (Invertebrates that lack hard appendages such as legs or antennae)
Arthropods jointed (the arthropods are the only invertebrates to have jointed appendages)
Echinoderms not jointed (Due to their radial symmetry, all echinoderms have appendages which point outward from the center of the body like the spokes on a wheel.)
and vertebrate jointed
It’s mass and speed. This is because the equation for Kinetic energy is KE=1/2mv^2
DNA is going to be the answer
Answer and Explanation:
Observing population directly gives you accurate result .
Direct observation does not need any intermediary as they themselves go for survey.
So, it is cost efficient.
Whereas indirect observing may involve manipulations.
It requires someone or many to hire who helps in surveying.
It incurs cost.
Thus, direct observation is always better than indirect observation.
