Download Classifying Animals Voc.and Notes Aug.29

Name _______________
Science Vocabulary and notes
Test- Friday, September 2, 2016
1. Bilateral symmetry is a body plan in which an organism can be divided along one plane
of its body to produce two mirror images.
2. A marsupial is a mammal in which the female has a pouch where offspring develop after
birth.
3. Radial symmetry is a body plan in which all body parts of an organism are arranged
around a central point.
4. A placental mammal is a mammal whose young develops within the mother.
5. Asymmetrical is something that cannot be divided into mirror images.
6. A monotreme is a mammal that lays eggs.
1. Simple invertebrates include sponges, cnidarians, and worms and they live in moist or
water-filled environments. Invertebrates have no backbone.
Sponges: Sponges have no true organization. They are the only animals without real tissues
or organs. They are asymmetrical.
Cnidarians: Jellyfish, sea anemones, corals, and hydras are all cnidarians. Cnidarians are
soft-bodied, aquatic creatures. They have radial symmetry. Cnidarians have tentacles,
muscle tissues, stinger cells, and a mouth.
Worms: There are three main groups of worms: flatworms, roundworms, and segmented
worms. All worms have bilateral symmetry. Flatworms have a flat body and head with
simple eyes and a mouth. Flatworms have only one body opening, undigested food leaves
its body through the mouth. Roundworms have simple digestive and nervous systems and
are some of the most abundant animals on earth. They often live in the bodies of other
animals. Segmented worms or annelids have a body plan that is divided into sections or
segments. They have a two-way digestive system and organs, including a stomach, a heart,
and a brain.
2. Complex invertebrates include mollusks, echinoderms, and arthropods. They live in
many different environments.
Mollusks all share the same body plan. They have a muscular foot or tentacles, a fold of
tissue called the mantle, and a mass of internal organs. They all have bilateral symmetry.
Mollusks include snails, clams, and squids. Most all mollusks have a shell, which is excreted
by the mantle. Mollusks have specialized organs, including gills, a heart, and a welldeveloped nervous system.
Echinoderm include sea stars, sea urchins, and sea cucumbers. Echinoderms have a
skeleton called an endoskeleton, located inside the body. Echinoderms usually have radial
symmetry. Echinoderms use a water pressure system that helps them feed, breathe, and
move.
Arthropods are the most numerous animal group on earth. This group includes spiders,
crabs, and insects. They are small and light with a hard skeleton on the outside of the body
called an exoskeleton. All arthropods have bilateral symmetry.
3. Vertebrates have a backbone. They have bilateral symmetry and endoskeletons. There
are four main groups of vertebrates: Fish, amphibians, reptiles, and birds.
Fish there are three classes of fish: Jawless fish, cartilaginous fish, and bony fish. Fish are
cold-blooded animals. They can’t automatically keep their body temperature steady.
Examples of jawless fish are lamprey and hagfish. Sharks, skates, and rays are cartilaginous
fish. Swordfish, tuna, and clownfish are bony fish.
Amphibians are cold-blooded animals. They spend part of their lives in water and part of
their lives on land. This class includes frogs, toads, and salamanders.
Reptiles are true land animals with one or two lungs. They thick, scaly, waterproof skin.
Reptiles include lizards, snakes, turtles, alligators, and crocodiles. They are cold-blooded.
Birds have two legs and two wings. They have hollow bones to reduce their weight and
feathers. Birds are warm-blooded animals.
Mammals milk, hair, and large brains are the key characteristics of mammals. All mammals
have hair or fur. Mammals are warm-blooded. There are three subclasses of mammals:
monotremes, marsupials and placental mammals.