It forms the outer layer of a cell. It gives an animal cell its shape. It is selectively permeable.
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our water pipes, and the led in some water sources.
I think the correct answer from the choices listed above is option A. It is the alveoli that is composed of single layer <span>surrounded by a network of capillaries. These are used to allow oxygen and carbon dioxide to move from the lungs to the bloodstream.</span>
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: Diffusion
Explanation:
Diffusion is the process or a spontaneous movement of particles from an area of higher concentration to an area of lower concentration.
Examples are;
1. perfume
2. A drop of ink in a cup of water.
From these two examples when it is dropped, especially ink, it diffused inside the entire space of the cup and fill all the space by penetrating the entire molecule of the water available.
