Answer:
it is because there is less oxygen and creatures need more oxygen to perform their work..
hope this helps you ☺️☺️
The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Okay what u want me to help you with
Answer:
The energy that was not passed on the next tropic level is lost as heat
Explanation:
In an ecosystem flow of energy occur from one tropic level to the next one as the organism of one tropic level eats another organism belongs to the tropic level that is lower from that of previous one.
The 10% of total energy of one tropic level is passed to the next tropic level the rest of the energy is lost as heat in the environment.
Answer:
B. Protein is composed of DNA which is produced in the cell
Explanation:
