Unit 3 Lesson 4 What Are Structural Adaptations? Copyright © Houghton Mifflin Harcourt Publishing Company 1

Unit 3 Lesson 4 What Are Structural Adaptations? Staying Alive An adaptation is any trait that helps a living thing to survive. Animals that are hunted for food are called prey. Animals that hunt prey are called predators. Predators and prey have adaptations that help them catch food or avoid being eaten. Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 3 Lesson 4 What Are Structural Adaptations? Staying Alive A horse has flat teeth that allow it to grind the grass that it eats. A tiger has sharp teeth that help it tear meat. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Staying Alive Unit 3 Lesson 4 What Are Structural Adaptations? 4 Copyright © Houghton Mifflin Harcourt Publishing Company 4

Staying Safe Unit 3 Lesson 4 What Are Structural Adaptations? 5 Copyright © Houghton Mifflin Harcourt Publishing Company 5

Unit 3 Lesson 4 What Are Structural Adaptations? Staying Safe Defense adaptations may attack a predator’s sense of sight, smell, taste, touch, or hearing. A bad taste, loud noise, or nasty odor is often enough to make a predator go away. Copyright © Houghton Mifflin Harcourt Publishing Company 6

Unit 3 Lesson 4 What Are Structural Adaptations? Staying Safe A porcupine raises its quills, swings its tail, and pokes its attacker to make it go away. A skunk’s spray has a bad odor. It’s a powerful defense against predators. Copyright © Houghton Mifflin Harcourt Publishing Company 7

Staying Safe Unit 3 Lesson 4 What Are Structural Adaptations? 8 Copyright © Houghton Mifflin Harcourt Publishing Company 8

Unit 3 Lesson 4 What Are Structural Adaptations? Creature Costumes Some animals can hide without trying. These animals are hidden by their shapes, colors, or patterns. Such disguises are called camouflage. A snow leopard’s spots help it blend into the background of snow and rock. Copyright © Houghton Mifflin Harcourt Publishing Company 9

Unit 3 Lesson 4 What Are Structural Adaptations? Creature Costumes What color should this lizard be to camouflage with the leaf? Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unit 3 Lesson 4 What Are Structural Adaptations? Creature Costumes Some harmless animals look like animals that are harmful to predators. Since predators don’t know which animal is harmful, neither gets eaten. Imitating the look of other animals is called mimicry. Monarch butterflies make birds sick. Viceroy butterflies mimic them to prevent getting eaten. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Creature Costumes Unit 3 Lesson 4 What Are Structural Adaptations? 12 Copyright © Houghton Mifflin Harcourt Publishing Company 12

Unit 3 Lesson 4 What Are Structural Adaptations? Plant Facts Plants need water. There isn’t much water in a desert, so desert plants are adapted to hold moisture. Desert plants such as cactuses have thick stems that store water. The leaves of many desert plants have a waxy coating that helps prevent water loss. Most desert plants have spines that help prevent water vapor from escaping from the plant. Copyright © Houghton Mifflin Harcourt Publishing Company 13

Plant Facts Unit 3 Lesson 4 What Are Structural Adaptations? 14 Copyright © Houghton Mifflin Harcourt Publishing Company 14