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.
The correct answer is natural selection. C is the answer!
Bacteria has a stronger resistance that usually produces even more resistant bacteria, and the cycle just repeats itself, making more and more resistant bacteria. This process is called Natural Selection.
Hope that helped!
-Chris
Hunting is regulated because plants still need to be eaten by the deer. if they arent, a plant species grows uncontrollably and kills off other plants.
2. A Mendelian trait is caused by a single gene. 3. Traits can be dominant or recessive and recur in a predictable pattern in subsequent generations. ... Autosomal Recessive Inheritance: Autosomal recessive traits can skip generations and can affect both sexes.
