UNIT: INVERTEBRATE ANIMALS 1º ESO BIOLOGY AND GEOLOGY

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1 UNIT: INVERTEBRATE ANIMALS 1º ESO BIOLOGY AND GEOLOGY 2015/2016 What do they have in common? What are their differences? What is the theme for the next unit? Vertebrates and Invertebrates 1

2 Label the animals with the pictures : Blue Whale Crab Monkey Owl Earthworm Frog Starfish Octopus Fun Facts about Invertebrates Around 23% of all marine organisms are mollusks. The only hard body part of an octopus is a hooked beak at the end of its tentacles. Some invertebrates, such as echinoderms, do not have heads. There are likely millions of invertebrates living in your house right now. They are called dust mites and you can't see them. When a crustacean outgrows its shell, it sheds the shell and grows a new one. Lobsters, crabs, and shrimp all have 10 legs. The front two legs have pincers they can use to catch food and fight off predators. Some scorpion mothers protect their young by carrying them on their backs. Centipedes are carnivores which eat insects and worms. They have a poisonous bite to help them kill their prey. Millipedes are herbivores who eat plants and rotting material. 2

3 WORDSEARCH 3

4 PORIFERA or SPONGES Lives in aquatic environments, mostly marine. All are filter feeders. They have an internal cavity and an upper hole called osculum. All are sessile Reproduction : sexual and asexual CNIDARIA They have a soft body. Body contains an internal cavity ( gastrovascular cavity ) connected to the mouth. The mouth is surrounded by tentacles. Two different forms exist, Jellyfish ( can swim ) and polyp ( are sessile) Reproduction : sexual and asexual. 4

5 WORMS Animals with a soft and elongated body. The most importants are : Phylum Platyhelminthes ( flat worm s ), Phylum Nematoda ( Nematodes ) and Phylum Anelida ( annelids, earthworm) Phylum Platyhelminthes ( flat worms ) They have got a long, flat, soft body. Tapeworms have got a body divided into rings. Some species occur in all major habitats, including many as parasites of other animals. Taenia is a parasite that lives in human intestines. Reproduction: sexual ; hermaphrodites ( have both male and female sex organs; can fertilise themselves) Phylum Nematoda ( Nematodes ) Bodies are soft and cilindrical. Live just about everywhere, many species are endoparasites. Reproduction : sexual Phylum Anelida ( annelids, earthworm) Soft and cilindrical body. The body is divided in segments. Earthworm breathe through the skin. Live in most environments. Reproduction: sexual. 5

6 MOLLUSCS Include aquatic and terrestrial invertebrates. Molluscs have these main characteristics: Head, contains sense organs. Body mass, has the main organs. Muscular foot, is used for moving, excavating. Shell, one or two valves, no shell. How many groups of molluscs are there? Gastropods, Bivalves and Cephalopods. Gastropods : spiral shaped shell. Examples: snails, sea snails and slugs. SNAIL SLUG Bivalves: The shell has two valves. Examples: clams, mussels, oysters. CLAM OYSTER Cephalopods : they have tentacles. Examples : squid ( internal shell); Octopus. SQUID 6

7 ARTHROPODS There are more than one million of species. They live in sea water, fresh water and on land. The main characteristics are: Body is covered by a rigid and articulated exoskeleton. Body is divided into segments: head, thorax and abdomen. Some of them have cephalothorax ( head + abdomen) Jointed appendages: legs, antennae, wings. Reproduction: sexual. Oviparous. Metamorphosis. How many groups of arthropods are there? Crustaceans, Myriapods, Arachnids and Insects Groups Examples Body/Appendages Habitat Crustaceans Lobster, Crab, Shrimp 10 legs aquatic Myriapods Centipede, Scolopendra worm like body, many legs terrestrial Arachnids Spider, Scorpion 8 legs terrestrial Insects Butterfly, ant, bee, wasp 6 legs, 2 antennae, 2 or 4 wings, no wings terrestrial, some aquatic LOBSTER SHRIMP SCOLOPENDRA SPIDER ANT WASP 7

8 ECHINODERMS They are marine invertebrates. They have the ambulacral system. The main function of the ambulacral system is locomotion. Echinoderms have different forms: rounded, cylindrical or like a star. Examples: starfish, sea urchins, sea cucumbers and brittle stars. SEA URCHIN SEA CUCUMBER BRITTLE STAR LISTENING : 1 Fill in the blank: The have an internal skeleton formed by, and the that have no. 2 Name 3 groups of invertebrates. 3 Fill in the blank: Many of the we use in the shower are invertebrate animals. 4 Fill in the blank: Worms are soft and long invertebrate animals that move by dragging their in the ground because they have no. 5 Fill in the blank: Some mollusks like snails, clams or mussels, protect their soft body with. 6 The echinoderms that have a star shape are called. 7 Fill in the blank: The are the most abundant animal on the earth. 8

9 Game : notebooks. Activity: In groups, look at the pictures and decide what type of invertebrate they are. Write your answers in your What type of invertebrate are they? 9

10 Activity Give examples of these invertebrates Porifera Worms Arthropods Cnidaria Molluscs Echinoderms RESOURCES