Answer:
The correct answer would be - observational approach.
Explanation:
Observation approach is the research technique that involves the observation of the subject or participates behavior in their natural habitat or state. This will be one of best approach to study.
Similarly when characterizing new findings various aspect of experimental, Observational details or modelling approaches will help in identification , classification and nomenclature. However, in comparison to experimental and modeling approach is more appropriate method for the rare endangered species.
Thus, the correct answer would be - observational approach.
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.
Answer:
Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.
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