After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Answer:
Solutes dissolved in water on either side of the cell membrane will tend to diffuse down their concentration gradients, but because most substances cannot pass freely through the lipid bilayer of the cell membrane, their movement is restricted to protein channels and specialized transport mechanisms in the membrane. Although ions and most polar molecules cannot diffuse across a lipid bilayer, many such molecules (such as glucose) are able to cross cell membranes. ... Channel proteins form open pores through the membrane, allowing the free passage of any molecule of the appropriate size.t is the proteins, therefore, that give each type of membrane in the cell its ... Many extend through the lipid bilayer, with part of their mass on either side ..... Many hydrophobic membrane proteins can be solubilized and then purified in an active, if not entirely ..... Many Membrane Proteins Diffuse in the Plane of the Membrane.
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Warning Dont copy all of this i just answered this question to give you idea of what it is
A virus can be inside a body without showing up
The answer is letter A.
Dogs grow a thick coat fur during winter because they are adapting to change. Adaptations are
the result of evolution in different living organisms. This process occurs amazingly
through gene mutation but it takes a very long period in time. Adaptation
processes occur to help species survive and thrive in the ecological balance of
life.
Structural adaptations are physical features of an organism that adapted
through time. An example of this is the thick coat of fur that dogs naturally grow to protect themselves from the change of the weather.
Answer: A
Explanation: A stream terrace basically forms through this process– Temporary base level is eliminated; the stream downcuts upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.