Answer:
The respiratory system is comprised of specialized organs and structures for gas exchange in both animals and plants. The structure and function of this system differ significantly based on the organism's size, habitat, and evolutionary background. In terrestrial animals, the respiratory surfaces are typically the linings of the lungs. In mammals and reptiles, gas exchange occurs within millions of tiny air sacs known as alveoli, while birds have atria for this process. These tiny air sacs boast an extensive blood supply, ensuring air comes into close proximity with the bloodstream. They connect to the outer environment through airways or hollow tubes, with the trachea being the largest that divides in the chest into two primary bronchi. These then branch further into successively narrower secondary and tertiary bronchi, eventually leading to numerous smaller tubes called bronchioles. In birds, these are referred to as parabronchi. The air needs to be drawn into the alveoli or atria from the outside through the act of breathing, which involves respiratory muscles.
Explanation:
Answer:
b. the composition of R groups varies among the 20 amino acids in proteins, which can be either polar or charged.
Explanation:
As proteins consist of numerous amino acids connected together, their connections occur uniformly across all amino acids because one segment remains identical among them all.
The remainder of each amino acid, known as the R group, differs across the various types, defining their unique characteristics and contributing to their chemical properties.
Cuando el agua es abundante (no limita), las plantas tienen la capacidad de poseer más estomas, lo que aumenta el acceso al agua (y a los iones de hidrógeno necesarios) y proporciona un mejor soporte a los tejidos herbáceos.
Espero que esta respuesta sea correcta :)