Answer:
Cnidarians are not considered to have coelm ecause they are diploblastic, so they don't have any mesodermic tissue.
An organelle is a function in the body.
Only the successful competitors will reproduce, mortality<span> is very high. Four (4) conditions for natural selection. Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population.</span>
a reaction where particular set of chemicals changes into another form without changing their nuclei just the transfer or sharing of electrons and formation and breaking of bonds is called as chemical reaction.
example- formation of water, photosynthesis etc.
but if there is a change in nuclei than it would be called as nuclear reaction.
like Uranium breakdown etc.
To help the nervous system and brain develop.