The proportions of nitrogenous bases in the DNA of two different human tissues (thymus and sperm) are . *

are about the same.

Explanation:

This is a great question! From our previous knowledge of biology, we can recall that all of the cells in an individual body began with a single cell.

It is worthy to note that the singular cell went though cell division more than once, that is to say it went through cell divison many, many times to produce around 50 trillion or so cells that comprises of an individual body. Almost all of the cells in your body share the same DNA as was found in that first cell*.

This explains why body cells and tissues in a certain individual entail the same DNA.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

gold i'm pretty sure i might be wrong