Answer:
The beating or fanning movements of three pairs of maxilliped flagella in crabs and crayfish modify exhalent gill currents while drawing water over chemoreceptors on the head. They play an integral part both in signalling by distributing urine odours, and in active chemosensation.
Explanation:
Water is the compound. Iodine and calcium are elements, and air is a mixture
Lipids are NOT made of nucleotides. Nucleotides are the building block for nucleic acid, if that answers your question.