Answer:
Red blood cells (erythrocytes)
Red blood cells carry oxygen from your lungs to your tissues. They also bring carbon dioxide back to your lungs. Red blood cells make up almost half of your blood. The lifespan of a red blood cell is around 120 days
Explanation:
The main food sources of the birds( the plentiful recourses within the environment occupied by the species)
Answer:
The structure of plant roots, stems, and leaves facilitates the transport of water, nutrients, and photosynthates throughout the plant.
Explanation:
Answer:
The atmosphere is a closed system
Explanation:
Because inside the atmosphere open system
Food is a basic need for all organisms
