Parasites benefit their hosts is the true statement. Parasitism is a symbiotic relationship in which one organism (the parasite) benefits from another organism and this other organism is harmed by the parasite.
The others aren't true because:
- the organism that is harmed doesn'y adapt and evolve it still is vulnerable
- it is a fact that parasites change from hosts
- phoresy is an association between two species in which one transports the other. This does not include killing the host (is possible, but it is not a condition under which you can call something a phoresy).
Answer:
cnidarians
Explanation:
Cnidarian is a phylum of organisms that comprises of the simplest forms of multicellular organisms. Examples of cnidarians includes; coral animals, jellyfish, and sea anemones among others.
They are soft-bodied, carnivorous animals that have stinging tentacles arranged in circles around their mouths. They are the simplest animals to have body symmetry and specialized tissue.
All cnidarians are aquatic, mostly marine organisms, and have two body layers that is the ectoderm and endoderm.
A MYSTERIOUS ailment has been devastating the much studied lions of the Serengeti National Park in Tanzania, and scientists said yesterday that it had been identified as canine distemper, a viral disease that causes severe neurological symptoms and death.
A. chemicals, the constriction of the pupil are usually caused by opiates anti-hypertension drugs.
