Which of the following is used for the preservation of specimens in a herbarium?

What is the process of spraying specific chemicals on dried plant specimens for their preservation called?

For identifying organisms through a key,usually:

Which of the following are true about the taxonomical aid 'key'?
$(a)$ Keys are based on the similarities and dissimilarities.
$(b)$ Key is analytical in nature.
$(c)$ Keys are based on the contrasting characters in pair called couplet.
$(d)$ Same key can be used for all taxonomic categories.
$(e)$ Each statement in the key is called Lead.
Choose the most appropriate answer from the options given below:

Why is the importance of botanical gardens increasing?

$A$ sheet of fixed size used for mounting plant specimens is known as...