poriferans and cnidarians

PORIFERS AND CNIDARIANS

Roberto jimenez pareja 1ªB

INDEX

1. Characteristics of poriferans

2. Characteristics of cnidarians

3.Animals and humans:3.1.Helpful poriferans/cnidarians: Corals 3.2.Harmful poriferans/cnidarians: Jellyfish

Characteristics of poriferans

Poriferans are commonly called sponges. These are multicellular organisms which are sessile/sedentary in nature. Most of them are marine while a few are fresh water forms. Body is cylindrical, asymmetrical or has radial symmetry.

Characteristics of cnidarians

Chidarians are aquatic organisms They have radial symmetry Cnidarians have a nervous system and a very simple musculature Chidarians are carnivores and trap their prey with their tentacles

3.

Animals and Human:

3.1

Helpful poriferans/cnidarians: Corals

Coral reefs provide food for millions of human beings. Corals, like trees for birds and other hosts, provide structure and substrate to house and feed fish and other marine life that are eaten by humans.

3.2

Harmful poriferans/cnidarians: Jellyfish

Jellyfish can cause harm to humans once they come into contact with swimmers who cross their path. The most obvious consequences of such unwanted encounters are bodily injury, or death, and also a reduction in coastal tourism.

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