Respiratory system helps in breathing and it leads to exhalation of the gas carbon dioxide which is not required by the body. The integumentary system is the first line of defense and protects the body from invadig microbes, dust, and other harmful substances. The digestive system protects the body by enabling digestio of food and providing energy to sustain, further the toxic waste materials are also released during the process.
One of the reasons why the fish population remains approximately the same from one generation to the next is because not all the eggs laid will survive to adulthood. There are several factors which bring about elimination of the the newly hatched eggs. Examples of these are predators and diseases which eliminate the young offsprings at different stages before they develop into adulthood.
Secondly, production of many eggs by the different fish species leads to competition for survival. Resources such as water, food, oxygen and shelter have to be fought for and its only the fittests that will be able to survive till the reproduction stage.
Explanation:
Evaporation-A phase change from a liquid to a gas
Melting-A phase change from a solid to a liquid
Freezing-A phase change from a liquid to a solid
Sublimation-A phase change from a solid to a gas
Hope this helped, lots of love,
-Kiddoo <3
