Answer:
The correct answer is option B ( ligand gated channels opened by neurotransmitter molecules).
Explanation:
Input region or postsynaptic region or dendrite is the site of neuron cell which receives the impulse from the pre-synaptic neuron at the synaptic junction.
The cell membrane of the dendrite is embedded with ligand-gated channels which opens up in response to the ligand (neurotransmitters) produced by the neurotransmitter vesicle of axon or output region of neuron.
The neuromuscular junction is such a case where acetylcholine receptors present in the dendrite opens in the presence of acetylcholine.
Thus, option B ( ligand-gated channels opened by neurotransmitter molecules) is the correct option.
 
        
             
        
        
        
Answer:
c. mitochondrion, virus, hemoglobin, glucose, water molecule
Explanation:
The mitochondrion is a membrane which is found in cytoplasm of eukaryotic cells. It is also known as power house of cells. This is largest from virus, hemoglobin, water molecule and glucose. 
Virus is second largest and is small infectious agent. It has capability to infect many organisms and living cells. Hemoglobin is protein which is present in red blood cells. Glucose is a type of sugar presence in the blood. Water molecule is composed of hydrogen and oxygen and is smallest among the others.
 
        
             
        
        
        
Well he looked at the contents and saw they some of them had similar shapes so
        
             
        
        
        
Answer:
Tt. TT
Explanation:
those are the only two possible, unless tall is a recessive trait, then it's tt
 
        
             
        
        
        
Answer:
They form crystals. 
They have higher enthalpies of fusion and vaporization than molecular compounds.
They are hard.
They are brittle.
Explanation: