Answer:
The earth system usually refers to the different ways in which various physical, chemical as well as the biological processes interacts with one another and it includes the land areas, oceans, atmosphere, minerals and also the different cycles such as carbon, nitrogen, sulfur and so on.
These processes are continuously taking place at, on and below the surface of the earth, maintaining an equilibrium. The life existing on earth is directly dependent on these conditions and on-going processes. When there occurs changes in these conditions, then the lives on earth are affected.
For example, the lives are dependent on the climatic conditions, and when suppose the concentration of green house gases and other toxic elements are increased in an ecosystem, then the temperature will eventually rise, and there reaches a point when it becomes difficult for life to sustain. The organisms will suffer from different diseases.
Thus, the growth of life on earth affects when there occurs changes in the earth's system.
Diatoms have cell walls composed of silicon dioxide.
A. silicon dioxide.
Answer:
Mitochondrial DNA is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate.
Explanation:
Answer:
A tan might indicate sun damage to the skin.
Explanation:
Tanning is the process by which the skin is exposed to the ultraviolet rays that comes from the sun with the purpose of producing a dark-brown coloration called a TAN.
A tan achieved by exposure to the sun can actually indicate that a person's skin is undergoing damage from the UV rays of the sun, hence, the skin responds by producing a protein called melanin, which protects the skin and later forms the dark coloration- tan. From this explanation, tan is got in response to a damaging signal received by the cell, hence, a tan might indicate sun damage to the skin.
External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.