Explain the following: Role of lymphoid organs.

Explain the following: Role of Na^+ in the generation of action potential.

Explain the following : Role of Ca^++ in the release of neurotransmitters at a synapse.

Briefly explain the following : Name any four organisms which play impotant role as biocontrol agents.

Explain the role of LH?

Briefly explain the following : Importance of organic farming.

Explain not more than 70 words: Role of lymphoid organs in immune respone

Which of the following is not a principle lymphoid organ?

Explain the following: Primary sex organs control the growth, function and maintenance of secondary sex organs.

Explain the terms Primary lymphoid organs and Secondary lymphoid organs with example.

Lymph nodes are secondary lymphoid organs. Explain the role of lymph nodes in our immune response.