2, because a theory is not a law that can not be changed, and new evidence can change a theory.
The thickness of the uterine lining , becomes very thick...because when the level of hormone progesterone reaches its highest levels. according to Dr.X on yahoo answers.
<span>
</span>
The most common organisms with exoskeletons are arthropods which include insects (bees, ants), arachnids (spiders) and crustaceans (lobsters and crabs).
<span>Vacuoles are organelles present in plant cells, some animal, and some prokaryotic cells. There is a difference in size between plant and animal cells. Plant cells usually have one large vacuole while animal cells have a number of small vacuoles. If the term "small vacuoles" is used for vacuoles in animal cells, then they are involved in overcoming the foreign particles, storage of waste and during the exocytosis, and invagination of the cell membrane during engulfing the bacteria.</span>
