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.
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular.Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall. When looking under a microscope, the cell wall is an easy way to distinguish plant cells.
Difference Between Plant And Animal Cells 1 Chloroplast. Like animal cells plant cells have mitochondria. 2 Cell Wall. Animal cells do not contain a cell wall while plant cells and fungi cells do. 3 Vacuole. Vacuoles are very large membrane-bound sacs within plant cells.
I would guess C, hope that helps!
Answer:
B) sympathetic and parasympathetic
Explanation:
e autonomic nervous system also called the vegetative nervous system is part of the peripheral nervous system which inervates smooth muscle and glands. Thus, it directly affects the function of internal organs and regulates functions such as the heart rate, digestion, respiratory rate, urination etc. This nervous system control is unconscious.
The autonomic nervous system is divided into: the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.
Parasympathetic nervous system works when organism is at rest so it is known as system responsible for "rest and digest functions". On the other hand, sympathetic nervous system works at active and stressful situations and it is known as "fight and flight" system.
The three most common elements are oxygen, carbon, and hydrogen
