Can multicellular organisms lack tissues and organs?

Yes, for example, parasitic worms — flat ones — lack respiratory and circulatory organs, tactile organs are undeveloped, this is due to a way of life — nutrition, respiration due to the host’s body.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.