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.
The people represented by the ends of the bell-curve are the most rare.
This could mean that if it's an iq curve the people at the ends have either a really high or really low iq etc.
Gametes
gametes is another word for sex cells
Answer: Asexual reproduction
Asexual reproduction is a mode of reproduction in which a single parent is involved to produce the offsprings. This occurs in simple organisms. This does not requires formation of gametes like sexual reproduction. The offsprings are identical to the parent organism. Here, mother colony of protists, volvox gives birth to daughter as only single parent is involved it is a asexual mode of reproduction.