Answer: Animals use only respiration, while plants use both photosynthesis and respiration.
Scientific law is observations and theory is explanation.
Answer:
Listen to pronunciation. (al-VEE-oh-ly) Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
Natural selection provides the outline of an explanatory theory." Biologists consider it to be a scientific fact that evolution has occurred in that modern organisms differ from past forms, and evolution is still occurring with discernible differences between organisms and their descendants.
The right answer is D (less responsive to antigens)
It is proven that, after puberty, thymus activity (an organ that is included in the lymphatic system, producing T cells that pick up antigens) decreases and that in adult and aged people the thymus has no role. Work done in humans indicate that in fact the cellularity begins to decline from birth in favor of lymphocyte perivascular spaces and connective and adipose tissue, which leads to a decrease in the capture of antigens.
