The phylum Arthropoda (from the Greek, arthron = joint + pods = feet) is the largest on earth today. It contains about 1,000,000 known species, which is at least four times the total of all other animal groups gathered. In addition, they have good adaptation to different environments, advantages in competition with other species, exceptional reproductive capacity, efficiency in performing their functions, resistance to toxic substances and perfect social organization, such as bees, ants and termites.
Noise pollution in large cities has long been the subject of many discussions about its detrimental effects on human health. More recently, the United Nations (UN) has reported its concern about increasing noise pollution at sea as well. Apparently, this pollution is affecting and endangering the survival of marine species.
Sperm, male sex gametes, are produced in the testicles. The testicles are in the scrotum, which looks flaccid and slightly wrinkled. It is important that they are located outside the abdomen because sperm are produced at a lower temperature than the rest of the body.
Polyplacophora class ("many plates"): The dorsal surface of these mollusks has a limestone reinforcement composed of partially overlapping plates. One representative is the chiton. They are all marine. Scaphopoda Class ("canoe-shaped foot") chiton: Small animals with an elongated conical shell.
Mammals need a nutritious and abundant diet because the metabolic costs of maintaining temperature are very high, but according to the diet, the digestive tract may have specific adaptations. In carnivores the digestive tract is simple because the proteins, lipids and minerals found in meat do not require specialized digestion.
The passages between the three physical states (solid, liquid and gaseous) are called physical state changes. Look at the following diagram and then read the explanations of each of these changes. Have you ever seen how on a hot day a piece of ice melts right out of the freezer? In this case, the solid state water quickly changes to the liquid state.