The following are the characteristics of Cnidaria:
1. The organisms have specialized stinging cells known as cnidocytes.
2. Two types of body plans exist, that is, polyp and medusa.
3. The phenomenon of alternation of generation is observed.
The following are the characteristics of Porifera:
1. The organisms lack symmetry.
2. The adult forms are sessile.
3. The organisms obtain food by filtering water.
Answer:
A
Explanation:
Mitosis results in 2 daughter cells, whereas Meiosis results in 4.
Answer:
the petrified log looks like the original tree.
Explanation:
A tree to be petrified first needs to be buried. An element laying on the surface can not be petrified because it is exposed to many different factors (such as<em> organisms, microorganisms, climatic conditions</em>, etc.), that affect the petrification process. So, in the case of a fallen tree, first, it needs to be covered by many sedimentary layers. Once it is underground, it also needs the presence of underground water and minerals. Water replaces the original organic material with minerals (silica, calcite, and pyrite). This replacement process results in the conversion of the woody material into a fossil of the original material. Very often, the tree details are so preserved that the fossil looks exactly like the original trunk.
Depending on the preservation degree, a fossil can be useful for different studies about the past.
