موضوع انجليزي عن
الماء للصف الثامن فقرة برزنتيشن بحث موضوع ملخص جاهز باللغة الانجليزية انشاء موضوع انجليزي عن ابدا قصير كيفية كتابة موضوع
تعبير باللغة الانجليزية توجيهي قواعد كتابة تعبير بالانجليزي طريقة سهلة لكتابة تعبير بالانجليزي
موضوع تعبير انجليزي يصلح لكل المواضيع كتابة تعبير بالانجليزي عن نفسك وصف تعبير انجليزي
يصلح لكل المواضيع موضوع انشاء شامل لكل المواضيع موضوع يصلح لجميع المواضيع موضوع
تعبير انجليزي جاهز برجراف ينفع لاى موضوع
موضوع انجليزي عن الماء تعبير عن الماء بالانجليزي قصير وسهل فوائد الماء بالانجليزي
قصير بحث عن الماء عبارات بالانجليزي طويل فوائد الماء للجسم قصير وسهل بحث انجليزي عن تلوث الماء فوائد شرب الماء بالانجليزي اهمية الماء بالانجليزي
مترجم تعبير عن الماء بالانجليزي ثالث ثانوي برزنتيشن عن الماء بالانجليزي برزنتيشن عن الماء بالانجليزي قصير عن المياه المياه المائية خمس سبع ثمان تسع اربع
جمل كلمات كلام مقال علمي مقدمة
Today, water, mainly represented
by the oceans, covers more than 70% of the surface of the planet and offers
more than 90% of the volume available for the living. But this water is salty
and has strict and constant specificities. Just under 300 000 living species
have been described in the marine environment, accounting for about 13% of the
total known diversity of the Earth's diversity. Water is essential for life and
life appeared in the ancestral ocean, there is a little less than 4 billion
years. Decisive events took place there, from the appearance of the nucleus of
the cell to the capture of microorganisms that had become symbiosis with
organelles and with multicellularity (metazoans). Later, sexuality will also
develop there, extraordinary machine to generate diversity. The second event in
the same direction will be the exit of the oceans, around 400 million years for
organized life. The differences between life in water and in the air are
fundamental for physical reasons such as density and viscosity of fluids, heat
capacity, oxygen content ... and the presence of water outside or outside.
Water is the universal biological solvent and the water content of living
organisms ranges from 4% for resistance forms to over 98% for some aquatic
groups. Confronted with the physical laws of osmosis, living beings have
developed two strategies during evolution regarding the regulation of water and
salt exchanges: intracellular isosmotic regulation, early crustacean life forms
and regulation. extracellular anisosmotic, from crustaceans to mammals and
birds. The composition of the internal environment of marine organisms is very
similar to that of seawater to certain groups of crustaceans that developed,
500 million years ago, a capacity for the first time to maintain osmotic
homeostasis. this also for the majority of vertebrates. If life comes out of
water by chance, it is not by chance that only certain groups succeed.
Exchanges of water and electrolytes, on the one hand between intra- and
extra-cellular media, on the other hand between internal fluids and the outside
world, are the result of osmosis and energetically expensive mechanisms. of the
living. A human needs 75 m3 of water during his life to satisfy his physiology,
his body varies in water content between 60 and over 70%, depending on age and
sex.
Today, if globally water resources
are not threatened (and still?), Drinkable and usable water is becoming
increasingly scarce and humanity must urgently take measures for its survival.
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