Answer:
First, the activity that humans execute that affects their ecosystem positively is reforestation. Second, the activity that humans execute that affects their ecosystem positively is hunting. Their effects rely completely in nature, however, one improves the ecosystem by making it greener and increasing the space nature has to grow, while the other impacts the ecosystem negatively by unbalancing the food chain.
Explanation:
The reasons behind this answer are that in the first place the ecosystem is a very sensitive environment that can be affected by a wide range of factors. In the first place, reforestation helps the environment have better conditions for the animals that live in it, as well as to provide the human race a better quality of air, water and feel better after living in a more natural ecosystem. While hunting breaks the ecosystem's balance because it allows the food chain of the ecosystem to break and allow a general modification.
The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. Memory B cells of the immune system will protect her from getting the same cold again.
In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centres of the secondary lymphoid organs.
Memory B cells circulate in the blood stream in a quiescent state, sometimes for decades. Their function is to memorize the characteristics of the antigen that activated their parent B cell during initial infection such that if the memory B cell later encounters the same antigen, it triggers an accelerated and robust secondary immune response.
Memory B cells have B cell receptors (BCRs) on their cell membrane, identical to the one on their parent cell, that allow them to recognize antigen and mount a specific antibody response.
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Answer:
a point in time, event, or experience when one has a sudden insight or realization:
Answer:
he organisms that can fix energy from inorganic sources into organic molecules are called autotrophs. Organisms that cannot make their food from inorganic sources but depend on energy rich organic molecules synthesized by autotrophs for their energy needs are called heterotrophs.
The only source of energy for all the ecosystems of the earth is the sun. Light falling on the plants is trapped by the producers or autotrophs in the presence of chlorophyll and is used in synthesizing the organic food called glucose by the process of photosynthesis. By photosynthesis radiant energy of sunlight is transformed into potential energy of food. A part of this energy is trapped by the producers while the rest of the energy is dissipated. The remaining part of energy which is used in the synthesis of plant biomass is called photosynthate which is then available to the next trophic level in the food chain that is the consumers or heterotrophs. In an ecosystem there is a unidirectional flow of energy.
