1. Memory cells that trigger a secondary immune response
2. Specific antibodies that remain concentrated in the bloodstream for life after the first infection event
3. Memory cells that trigger a primary immune response
4. T cells that trigger a primary immune response
Answer:
1. Memory cells that trigger a secondary immune response
Explanation:
During the first infection when the body is invaded by a particular antigen, the immune system tries to identify the type of antigen. B lymphocytes make antibodies when the antigen has been identified in the event of a primary infection. The response of the immune system during the primary infection of that pathogen is usually slow. As soon as the primary infection is arrested by the antibodies produced in response, memory cells such as the memory B cells is formed, which enables the immune system to identify the same pathogen, and thereby triggers a faster secondary immune response in subsequent infections by the same pathogen.
Answer:
The law of conservation of energy states that energy
Explanation:
It can neither be created nor destroyed or only converted from one form of energy to another. This means that a system always has the same amount of energy... unless it's added from the outside. I hope this helps.
The right answer is 4).
The cytoskeleton is made up of biological polymers of proteins, sometimes called fibers because of their large size at the cellular level. They are classified into three categories:
Microfilaments: involves in cytoplasmic phenomena (division, endocytosis, migration).
Intermediate filaments: Maintenance of the nucleus structure.
Microtubules: Involved in the separation of chromosomes during mitosis.
Bacteria converts the ammonia and ammonium into nitrates and nitrites is described below.
Explanation:
1. Nitrifying bacteria convert ammonia to nitrites or nitrates. Ammonia, nitrites, and nitrates are all fixed nitrogen and can be absorbed by plants. Denitrifying bacteria converts nitrates back to nitrogen gas.
2. The nitrification process requires the mediation of two distinct groups: bacteria that convert ammonia to nitrites (Nitrosomonas, Nitrosospira, Nitrosococcus, and Nitrosolobus) and bacteria that convert nitrites (toxic to plants) to nitrates (Nitrobacter, Nitrospina, and Nitrococcus).
3. Nitrifying bacteria present in the soil convert ammonia into nitrite. Nitrite is then converted into nitrate. This process is called Nitrification.
4. De-Nitrification: Nitrogen in its nitrate form (NO3–) is converted back into atmospheric nitrogen gas (N2) by bacterial species such as Pseudomonas and Clostridium, usually in anaerobic conditions. These bacteria use nitrate as an electron acceptor instead of oxygen during respiration
