Answer:
b. The surfaces of the membrane are nonpermeable.
Explanation:
This helps the cell membrane to protect the cell.
 
        
                    
             
        
        
        
Answer:
a The pulmonary artery carries deoxygenated blood.
Explanation:
This is the the only artery that transports deoxygented blood in mammals. specifically it carry deoxgenated blood from the the atria  to the pulmonary circulation. That is to the lungs  for the exchange of the C02 in the deoxygenated blood with oxygen  in the lungs.
The  blood thus become oxygenated,and therefore return through the pulmonary veins to the left ventricle.
From the left ventricle ,through ventricular systole,blood is empty into the aorta through the aortic valves into the  systemic circulation.
Although,they carry blood away from the heart,but the blood is de oxygenated instead of the usual oxygenated by arteries,They are still regarded as arteries  because of convey of blood away from the heart,a typical role of arteries
 
        
             
        
        
        
Answer:
The testes are two oval-shaped male reproductive glands that produce sperm and the hormone testosterone.
 
        
                    
             
        
        
        
First answer is , as the work of ventricle is to push blood to he whole body , so it has to be strong or it can not pump blood to head to the toe !
as in frog (an amphibian ) it has only three chambers as two artia and one ventricle, so the oxygenated blood from left artia and deoxygenated blood from right , combines and thus partial oxygenated blood is circulated !
        
             
        
        
        
Answer:
a fuel for cellular respiration and a starting material for making other organic molecules.
Explanation:
Plants have the ability to produce sugars by the process of photosynthesis. Plants can convert the inorganic CO2 from the air into the organic nutrients such as sugars. Plants store sugars so that they can serve as a source of ATP for the cells as and when required. The sugars enter the process of cellular respiration and are oxidized into CO2 and H2O. In addition, the energy of chemical bonds of the sugars is used to form ATP molecules.
Plants also use sugars to synthesize other organic molecules. For example, several intermediates of Kreb's cycle can serve as precursors for the synthesis of amino acids. Amino acids are joined together to form different proteins.