Professional antigen-presenting cells, such as phagocytes, are the first cells to encounter a pathogen (apcs). This means they have the ability to activate cells of the adaptive immune system.
<h3>What is meant by Pathogen?</h3>
- A pathogen is an organism that infects its host with disease, and the severity of the disease symptoms is referred to as virulence.
- Pathogens include viruses, bacteria, unicellular and multicellular eukaryotes, and a wide range of other organisms.
- The bone marrow of an average healthy adult generates 100 billion new neutrophils per day. Because there are so many neutrophils in the body at any given time, they are often the first cells to reach the site of an infection.
- Long thought to be a component of the innate immune system, complement has recently emerged as an important regulator of the adaptive immune response.
Therefore the correct option is D) can activate cells of the adaptive immune system.
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The answer is B. Cnidarians
Cnidarian body has no left or right side, only tom and bottom surfaces. If you divide cnidarian a about central point, you will get equal parts. So, cnidarians are radially symmetrical animals. This group includes hydroids, jellyfish, anemones, and corals. In all groups, animals have stinging cells on tips of tentacles. They use them to capture the prey. Their name literally means stinging creatures.
The energy for ATP synthesis comes from organic molecules (such as carbohydrates), or from sunlight, or from inorganic electron donors. We can classify organisms according to their source of energy and organic carbon:
<span><span>heterotrophs – get energy and organic carbon from metabolism of pre-existing organic compounds (food)</span><span>photoautotrophs – use energy from sunlight to make ATP and their own organic carbon compounds from carbon dioxide chemoautotrophs</span><span> – use energy from inorganic chemicals to make ATP and their own organic carbon compounds from carbon dioxide</span></span>
Metabolic pathways carry out reactions that capture energy from these various sources (organic compounds, sunlight or chemicals) and couple them to synthesis of ATP from ADP.