Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Unlike other animals, they lack true tissues and organs, and have no body symmetry.
The shapes of their bodies are adapted for maximal efficiency of water
flow through the central cavity, where it deposits nutrients, and leaves
through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silicon dioxide. All sponges are sessile
aquatic animals. Although there are freshwater species, the great
majority are marine (salt water) species, ranging from tidal zones to
depths exceeding 8,800 m (5.5 mi).
The human heart has only 4 chambers. Left and right atria and left and right ventricles.
<u>Smoking</u> causes respiratory disorders such as bronchitis, pneumonia and lung cancer.
<u>Explanation:</u>
Respiratory disorders such as bronchitis, pneumonia and lung cancers are caused by smoking tobacco, air pollution and by infection. Smoking is the predominant cause of this respiratory order it also raises the level of air pollution which becomes hazardous to all the living organisms.
Infection in the lungs which is identified as pus in air sacs and found as inflamed lungs is usually life threatening. Severe shortness of breathe called the bronchitis is due to airborne chemicals.
The BRAIN. All of the senses send message to the Brain
Mitochondrion because it’s the powerhouse of the cell.
