Answer:
The answer is actually B) Memory T. Memory T cells rapidly produce large numbers of effector T-cells when re-exposed to their antigens, which provides the immune system memory against past infections.
Answer:
Process of Green Revolution
Explanation:
Photorespiration limits casualty products of light reactions
that build up in the absence of the Calvin cycle. In many plants,
photorespiration is a problem because on a hot, dry day it can drain as much as
50% of the carbon fixed by the Calvin cycle. The closing of stomata reduces access to CO2
and causes O2 to build up. These conditions favor a seemingly not useful process
called photorespiration. In most plants
(C3 plants), initial fixation of CO2, via rubisco, forms a three-carbon
compound. In photorespiration, rubisco
adds O2 instead of CO2 in the Calvin cycle. Photorespiration eats up O2 and
organic fuel and releases CO2 without producing ATP or sugar. Photorespiration
can evolve relic because rubisco first evolved at a time when the atmosphere
had far less O2 and more CO2.
The question is incomplete. Th ecomplete question is as following:
All of the following protect the skin and mucous membranes from infection EXCEPT
A) multiple layers of cells.
B) tears.
C) saliva.
D) HCl.
E) the "ciliary escalator."
Answer: D) HCl.
Explanation:
- The epidermis, the outer layer of the skin provides waterproofing and serves as a barrier to infection and other laers also sustain any type of injury.
- Tears wash out foreign bodies which enter the eye. In addition, tears contain a substance called lysozyme which has an antibacterial function and works to prevent microbial invasion and infection.
- Saliva protects against infection, especially via the innate immune system. This mechanism is an important first-line protection against bacterial and viral infection
- The mucociliar escalator is within the conducting airways and is composed of mucus and cilia that transfer the mucus up and out of the lungs where it can be removed by coughing or swallowing,
Whereas HCL helps in the digestion process.
Hence, the correct option is D.
