Unit 4 Lesson 5 How Do Animals Grow and Reproduce? Copyright Houghton Mifflin Harcourt Publishing Company

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3 Meerkats

4 Have a Backbone? How are birds and fish similar? One of the major factors scientists use when classifying animals is whether an animal has a backbone.

5 Have a Backbone? Vertebrates are animals with backbones. Most backbones are made up of bones that are linked together and are flexible. Vertebrates can be grouped into five classes: mammals, birds, reptiles, amphibians, and fish.

6 Have a Backbone?

7 Have a Backbone?

8 Have a Backbone?

9 Have a Backbone?

10 Have a Backbone?

11 Q1 Have a Backbone?

12 Have a Backbone?

13 Spineless Invertebrates Animals without backbones are invertebrates. Invertebrates vary from very simple sponges to complex insects. Annelids

14 Spineless Invertebrates The simplest invertebrates are: 1. Porifera ex. corals, sponges. 1. Annelids ex. Earthworms are invertebrates that break down materials in soil. 2. Cnidarians ex. jellyfish.

15 Spineless Invertebrates 4. Mollusks, such as the whelk, are more complex. Many have shells to protect their soft bodies. Squid have internal shells and octopi have no shells.

16 Spineless Invertebrates 5. Echinoderms, such as sea urchins and sea stars, are invertebrates that live in salt water. When fully grown, they have body parts in multiples of five.

17 Spineless Invertebrates 6. The arthropod group, which consists of: A. Crustaceans. B. Spiders (Arachnids). C. Insects, is the largest group of invertebrates.

18 Spineless Invertebrates 6. Arthropods A. Crustaceans have hard exterior shells and five pairs of jointed limbs.

19 Spineless Invertebrates 6. Arthropods B. Arachnids like spiders have two body segments and eight legs.

20 Spineless Invertebrates 6. Arthropods C. Insects have antennae, jaws, and three body segments. There are more insect species on Earth than all other animal species combined.

21 Spineless Invertebrates Invertebrates game:

22 Spineless Invertebrates

23 Communication Is Key Communication is key to animal life. Interpreting animal communication lets scientists understand how animals live. 1. Some animals communicate using chemicals that other animals can smell. Smell can help animals communicate danger, find mates, or mark boundaries.

24 Communication Is Key 2. Some animals communicate using visual cues by changing colors or using movement to send messages.

25 Communication Is Key 3. Some communicate by making sounds.

26 Communication Is Key

27 Stages of Life All living things go through different stages. These stages make up the life cycle of an organism. Every life cycle begins with a fertilized egg. In some animals, like birds or reptiles, the egg may be enclosed in a hard or leathery shell that hatches. Most mammals develop inside the mother s bodies.

28 Stages of Life The development of an organism can happen quickly or over years. An organism grows larger and changes as it develops. When the organism is an adult, it is able to live on its own. Now the organism can reproduce, or make its own offspring. The organism will continue to age. Eventually, it dies.

29 Stages of Life

30 It s Time For a Change Metamorphosis is a process that occurs when organisms completely change form as they grow. In complete metamorphosis, an insect goes through four different stages in its life cycle. First, the insect begins life as an egg. Then, the egg hatches to produce a larva. The larva eats and grows in size.

31 It s Time For a Change Next, a larva develops into a pupa. Since pupa don t move, this is called the resting stage. In this stage, the pupa is undergoing dramatic changes. Finally, the adult emerges from the pupa. The adult insect can fly and reproduce.

32 It s Time For a Change

33 It s Time For a Change Another type of metamorphosis that occurs in some insects is incomplete metamorphosis. It has three stages: the egg, the nymph, and the adult. During the nymph stage, the insect looks like a smaller version of the adult, but it cannot fly or reproduce. As it grows, the nymph molts, or sheds its outer shell. The nymph molts several times until it finally becomes an adult.

34 It s Time For a Change

35 It s Time For a Change Metamorphosis is not limited to insects. Frogs also undergo the process as they develop from egg to tadpole to adult.

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