Answer:
The benefits provided by forest ecosystems include: goods such as timber, food, fuel and bioproducts. ecological functions such as carbon storage, nutrient cycling, water and air purification, and maintenance of wildlife habitat. social and cultural benefits such as recreation, traditional resource uses and .
Answer:
C
Explanation:
They lost their ability to see
Answer: CLONAL SELECTION OF B CELLS.
Explanation: B cells are also known as B lymphocytes( a type of white blood cell),when antigens binds to receptors in the cell,B lymphocytes in the body recognizes this antigen and selection is made from the pre-existing pool of different antigens,each with it's unique specification,this B lymphocytes undergo reproduction and from there a clonal population of cells are formed which kills/get rid of the antigen.
These antigens are eliminated by either the plasma cells that form immediately from the B lymphocytes secreting antibodies that fight the antigen,but in AIDS (people living with AIDS),the B lymphocytes that fight the antigen are known as memory B cells which are long lived from the stage of proliferation and are left to fight antigens in later life by forming plasma cells.so even if the helper T cells in AIDS patients are low,the memory B cells are stimulated to form plasma cells,activate antibodies to fight off life threatening infections.
<span>a) With sincerest and warmest regards
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