The sun is the source for photosynthesis
I am more of a chemistry person, but my best answer is the double-helix structure. The DNA rotate around a central point allowing it to keep a constant distance
Answer:
B)attach specifically to host cell receptors
Explanation:
Viral spikes are one of the envelope proteins. These proteins are coded for by viral genes. Viral spikes project from the envelope surface. They are also called peplomers. One of the functions of these spikes is to specifically interact with the receptors present on the surface of the host cell to mediate the attachment of the virus to the host cell surface. Viral spikes and the host cell surface receptors are complementary to allow their specific binding. For example, the spike protein of the SARS-coronavirus bind specifically to the human host cell receptor ACE2.
Answer:
c , b , a
Explanation:
The sequence in which the action would pass through points c, b , a.
An increase in A produces and increase in X
This is a positive feed back mechanism. This mechanism enhance or amplify changes. This tends to alter the balance away from equilibrium because one hormone will increase the release of the other hormone. An example of this is the child birth. During labor, oxytocin is released to increase the uterine contraction the release of oxytoocin will be induced by the contractions of uterus. This will go on until the child was born. Just remember positive feedback enhance the original stimulus.
