2.  calvin

3.  oparin

4.  smith and neil

2.  Secretion of saliva

3.  Secretion of digestive juice

4.   All of these

2.  Cl –

3.  Na-

4.  Ca2+

1.  nerve is covered with myelin sheath

2.  Neurilemma is discontinuous

3.  neurilemma and myelin sheath are discontinuous

1.   Retinol

3.  melanin

4.   Sclerotin

2.   ninth

3.  seventh

4.  fifth

1.  SNS, involuntary

2.  SNS, voluntary

3.  PNS, involuntary

1.   motor neurons and sensory neurons

2.  sensory neurons and association

4.   motor neurons and association neurons

1.  yellow spot

3.  pars optics

4.  None of these

1.  mechanical impulse

2.  chemical impulse

4.  magnetic impulse