Cell-to-cell communication is absolutely essential for multicellular organisms. but how do plants communicate when their cells are surrounded by cell walls? plants use for long-distance signaling, such as ethylene which promotes fruit ripening and regulates growth. a) hormones b) ions c) neurons d) phospholipids

Ans.

Cell-to-cell communication allows signalling of essential substances between the plant cells, which are surrounded by cell walls. The molecules used by plants for long-distance signalling are known as hormones, such as auxin, ethylene, and gibberelin.

These hormones are secreted by one plant cell and received by another plant cell, where it exerts it affect. Thus, the correct answer to be fill in the blank is 'option A). hormones.'

Explanation:

d bonding propertys

explanation:

carbon can form so many different compounds not just with oxygen

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.