The first one because just think about how light oxygen or air is
No system is closed off by it surroundings.
Answer:
eukaryote cells have a membrane -bound nucleus and prokaryote cells do not. the nucleus is where eukaryote ls store their genetic information and prokaryotes have no membrane bound organelles.
Answer:
The vascular system
Explanation:
The human blood circularitory system can be used to explain capillary action in the human body, our heart pumps blood in and out with no use of external forces.
Answer:
Glucagon signals the liver to start producing glucose.
Explanation:
Glucagon signals the liver to start producing glucose from the breakdown of amino acids through gluconeogenesis process. When the glucose level decreases in the body due to fasting or starvation, the pancreas release glucagon which provides signals to the liver to produce glucose form non carbohydrates substances present in our body. This production of glucose increases the concentration of glucose in the blood and the body used this glucose for the generation of energy molecules in the form of ATP.