What are the 1st and 2nd line of defence of plant against pathogens?

These may be:

Explanation:

Plants employ several methods in order to defend themselves from pathogens. These may be physical defenses or chemical ones. Several have adaptations to their surfaces that prevent the entry of pathogens, called physical barriers such as

Chemical defenses include the production or secretion of:

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

answer; i believe the correct answer is (a)0