Answer:Option B
The memory response is due to long lived cells that can respond rapidly to second exposure.
Explanation:
Immunological memory is the ability of the immune system to quickly identify and remember an antigen from a pathogen that the body has encountered before and initiate a faster immunological response upon a reencounter with the particular antigen. This dependents on colonial selection.. The memory cells have a long life span and can remain in the body for a long time. When it encounter the antigen its previously encountered for the second time, they mobilize quickly and become plasma cells, these secrets a lot of antibodies and cause a stronger reaction to defend against such antigen in a short time.
Answer: C
Explanation: The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days.
Answer:
Explanation:
The detailed steps are as shown below
- but magnitude of force F = √ [ 1 - v²/c²]
but acceleration twice as great as the force required to produce the same acceleration;
4 = 1 / [ 1 - v²/c²]
1/4 = 1 - v²/c²
v²/c² = 3/4
v/c = √ [3/4]
v = 0.87c
but speed of light c = 3 x 10^8m/s
v = speed of the particle = 0.87( 3 x 10^8m/s)
v = 2.61m/s
Yes it is in consideration all catalysts are of biological origin because biology is just a large term for a certain type of science.