Classifying Animals Vertebrates and Invertebrates Mrs. Christman

Objective Explore how to classify animals. Understand that animal cells are organized into tissues, organs, and systems. Describe observable characteristics of vertebrates and invertebrates. Classify animals by using a key.

Main Idea While all animals’ cells have similar basic structures, the specific structure and function of these cells are very diverse. The more cells, tissues, organs, and systems that organisms have in common or that are similar, the more closely related they are.

Vocabulary tissue-similar cells that have the same job or function organ- a group of tissues that work together, like a heart or brain. system- a group of organs that work together to do a certain job. For example, a mouth, stomach, and intestines make up the digestive system of an animal.

Classifying Animals Scientists classify animals based on cell structure, how cells are organized into tissues, how tissues are organized into organs, and how organs are organized into systems.

Classifying Animals Scientists look at the similarity of certain traits to classify animals. For example, at first glance a bat and an eagle may seem more alike than a bat and a cat. However, a bat and an eagle are very different. The bat and cat are both mammals. Both have hair and both feed their young mother’s milk. Birds on the other hand, are not mammals. Birds do not have fur and do not fee their young mother’s milk.

Vertebrates and Invertebrates Animals are divided into two large groups. One group is made up of animals that have backbones (vertebrates) The second group are animals that do not have a backbone. They are called invertebrates.

Sponges One of the simplest kinds of animals is a sponge. Belong to a group called Porifera. Have tissues but no organs. No stomach, mouth, or other organs Body is covered with pores (holes) Most live in oceans

Invertebrates with Stinging Cells Belong to Cnidaria group They have tentacles-long threadlike structures that make poisons. They have a mouth They live on the ocean floor jellyfish Sea anemone coral

Flatworms Belong to a group Platyhelminthes Have flat bodies Have heads and tails Most flatworms do not have true organ systems Flatworm

Roundworms Belong to a group Nematoda Have heads and tails Unlike flatworms, roundworms have round bodies, a digestive systems, and a simple nervous system. Live all over earth, inside plants, and animals Some worms can grow to 30 METERS long Roundworms

Earth Worms Belong to a group called segmented, or Annelida Have heads and tails. Many segmented worms have eyes and other specialized organs, such as jaws or gills Have circulatory, digestive, and nervous systems They can grow back parts if they lose parts. An earthworm has hairs on it to help it go through the dirt

Invertebrates with Soft Bodies octopus Snails, clams, and octopuses belong to the mollusks group Most have a shell either inside or outside their body. They make their shells from minerals in the water. Have three main body parts, a kind of foot, a tissue covering called a mantel, and a compartment holding internal organs. snail squid

Invertebrates with Soft Bodies octopus They live on land and fresh water and ocean water. They have gills for breathing. They have jaws or other organs for capturing food. Have a circulatory system. More complex mollusks, like octopuses, have a well-developed brain. snail squid

Invertebrates with Spiny Skins Unlike arthropods, the Echinodermata, or echinoderms, have a skeleton inside their bodies They have bodies with at least 5 sections They have suction cup feet to walk They use tubes to catch food to.

Arthropods There are 4 groups There are more arthropods on Earth than any other kind of animal.

Arthopods They have keen sense organs They have exoskeletons, a tough outer skeleton. They have jointed legs, and a body made up of two, three, or more sections.

Crustaceans They have five pairs of legs They live near or on the ocean floor Live on land and water They have antennae

Arachnids Spiders mites and ticks. 4 pairs of legs Most live on land. Some live in fresh water They are called parasites.

Insects Largest group of arthropods 3 pairs of legs 3 main body part sections 2 pairs of eyes Have mouths

Millipedes & Centipedes Many body segments Live under rocks & dark places Really have less than 100 legs Protects itself by curling up Millipedes have 4 legs on each segment Centipedes have 2 legs on each segment millipede centipede